removing "about" tab from "Settings" page

[kjozwiak]

Description

We should remove the About tab from the Settings page under brave://wallet as per https://github.com/brave/ethereum-remote-client/wiki/Testing, specifically the following:

 There should be no About tab present

Most of these links are pointing to MM pages.

Steps to Reproduce

1. launch brave and create a crypto wallet under brave://wallet
2. once you've created the wallet, click on the profile avatar and select Settings

Actual result:

Expected result:

As per https://github.com/brave/ethereum-remote-client/wiki/Testing, we should remove the About tab from Settings under brave://wallet. Or we should at least remove/change the links so they're pointing to Brave websites.

Reproduces how often:

100% reproducible using the above STR.

Brave version (brave://version info)

Brave	0.69.131 Chromium: 77.0.3865.90 (Official Build) (64-bit)
Revision	58c425ba843df2918d9d4b409331972646c393dd-refs/branch-heads/3865@{#830}
OS	macOS Version 10.14.6 (Build 18G95)

Version/Channel Information:

• Can you reproduce this issue with the current release? N/A (not released yet)
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the dev channel? Yes
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

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

Miscellaneous Information:

CCing @ryanml @bbondy @rebron @tomlowenthal @brave/legacy_qa

[srirambv]

possible dupe of #6101

[kjozwiak]

Yup, worded differently but definitely a dupe as per #6101 (comment).