Add window.phantom.solana alias

[darkdh]

Resolves brave/brave-browser#24192

doc update: brave/brave-wallet-docs#67

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

Adapter

1. Navigate to https://solana-labs.github.io/wallet-adapter/example/
2. Click "Select Wallet" and choose Phantom
3. Click "Connect"
4. Should be able to prompt for granting permission.

OpenSea

1. Navigate to https://opensea.io/
2. Click Wallet icon and select Phantom
3. Should be able to prompt for granting permission.

[srirambv]

Verification passed on

Brave	1.44.3 Chromium: 104.0.5112.57 (Official Build) nightly (64-bit)
Revision	212fd173a0da1e0a024f328295bb56a2529190bb-refs/branch-heads/5112@{#1042}
OS	Windows 11 Version 21H2 (Build 22000.795)

• Verified steps from PR description
• Verified able to prompt for granting permission when selecting Phantom as wallet provider on Dapps

Adapter	OpenSea
14282-Adapter.mp4	14282-OpenSea.mp4