Add support for tipping Github users (Github inline tipping)

[jdkuki]

Description

Feature request:
GitHub inline tipping should be enabled in several aspects of the GitHub website.
See screenshots/below specification document for affected ares.

Supported Areas:

https://github.com/<user>/<repository>/issues/<issue_number>
https://github.com/<user>/<repository>/pull/<pr_number>
https://github.com/<user>?tab=stars
https://github.com/<user>/<repository>/commits/<branch_name>
https://github.com/orgs/<org>/people
https://github.com/orgs/<org>/teams/<team_name>/members
https://gist.github.com/<user>/<gist_number>

Steps to Reproduce

1. Join Rewards
2. Browse to user profile (ex. github.com/jdkuki)
3. Click "stars tab"
4. Tip buttons should appear next to star button
5. Click tip button
6. Tip banner should appear with text "(profile_name)* on GitHub". Name should correspond to creator
   of starred item
7. Select tip amount and send
8. Transaction should show up in pending contributions or balance should update according to
   publisher verification status
9. Navigate to brave://rewards
10. Under tips settings, uncheck "GitHub"
11. Open pages with injected tip buttons should see tip buttons disappear.

*If profile name is not set, banner will display username handle instead

Screenshots

Please reference specification for exact appearance. Few examples:
PR

Issues

Commits

Actual result:

n/a

Expected result:

Reproduces how often:

Brave version (brave://version info)

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Can you reproduce this issue with the beta channel?
• Can you reproduce this issue with the dev channel?
• Can you reproduce this issue with the nightly channel?

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

[LaurenWags]

Verified passed with

Brave	0.69.130 Chromium: 77.0.3865.90 (Official Build) (64-bit)
Revision	58c425ba843df2918d9d4b409331972646c393dd-refs/branch-heads/3865@{#830}
OS	macOS Version 10.13.6 (Build 17G5019)

• Verified STR from description for each of the affected areas (also listed in the description)
• Encountered Add Media Box to GitHub inline tipping banner #5562
• Verified tip button on https://github.com/<org>/<repository>/issues/<issue_number>

* Verified tip button on PR

* Verified tip button on stars tab of user profile

* Verified tip button on commits > branch name

* Verified tip button on people page of org

* Verified tip button on team members page

* Verified tip button on gists

* Verified tip banner showed `profile name on GitHub` if existed and `username on GitHub` if it did not

* Verified tips showed in panel or pending where appropriate (based on established states):

Verification passed on

Brave	0.69.131 Chromium: 77.0.3865.90 (Official Build) (64-bit)
Revision	58c425ba843df2918d9d4b409331972646c393dd-refs/branch-heads/3865@{#830}
OS	Ubuntu 18.04 LTS

• Verified STR from description for each of the affected areas (also listed in the description)

• Encountered Add Media Box to GitHub inline tipping banner #5562

• Verified tip button on an issue
  

• Verified tip button on PR
  

• Verified tip button on stars tab of user profile
  

• Verified tip button on commits > branch name
  

• Verified tip button on people page of org
  

• Verified tip button on team members page
  

• Verified tip button on gists
  

• Verified tip banner showed profile name on GitHub if existed and username on GitHub if it did not
  
  

• Verified tips showed in panel or pending where appropriate:
  
  

Verification passed on

Brave	0.69.131 Chromium: 77.0.3865.90 (Official Build) (64-bit)
Revision	58c425ba843df2918d9d4b409331972646c393dd-refs/branch-heads/3865@{#830}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

• Verified STR from description for each of the affected areas (also listed in the description)
• Encountered Add Media Box to GitHub inline tipping banner #5562
• Verified tip button on https://github.com/<org>/<repository>/issues/<issue_number>

• Verified tip button on PR
  

• Verified tip button on stars tab of user profile
  

• Verified tip button on commits > branch name
  

• Verified tip button on people page of org
  

• Verified tip button on team members page

• Verified tip button on gists
  

• Verified tip banner showed profile name on GitHub if existed and username on GitHub if it did not

• Verified tips showed in panel or pending where appropriate (based on established states):

• Pending list of contributions

[forresthopkinsa]

IMO it's essential that we have the option to tell Brave to publish the tip on the relevant issue / PR / commit.

It's just not rewarding at all to send someone a tip and not know if they'll ever receive it – additionally, I want them to know who the tip is from and why it was sent to them. (Anecdotally, I installed the Brave browser and registered an Uphold account purely because I want to reward various developers for fixing bugs I reported)

It might be silly, but it is such a critical factor for the human aspect of tipping that I'm tempted to use Gitcoin's system instead, even though it's so much more clunky.

Potato quality example of what I'm talking about, taken from the above video:

[bsclifton]

cc: @Miyayes RE: above feedback (possible feature request)