Lazy load Brave Crypto Wallets

[bbondy]

Fix brave/brave-browser#9757
Fix brave/brave-browser#8121
Fix brave/brave-browser#6595
Fix brave/brave-browser#8860
Fix brave/brave-browser#8925

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Android
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that these changes pass automated tests (unit, browser, security tests) on
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that all lint errors/warnings are resolved (npm run lint)
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone
• Public documentation has been updated as necessary. 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-issues-with-tracking-protection
  • https://github.com/brave/brave-browser/wiki/QA-Guide

Test Plan:

See first issue above.

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

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.

[ryanml]

++ good stuff

[srirambv]

Verification passed on

Brave	1.11.25 Chromium: 81.0.4044.138 (Official Build) nightly (64-bit)
Revision	8c6c7ba89cc9453625af54f11fd83179e23450fa-refs/branch-heads/4044@{#999}
OS	Linux

Test for #9757

Scenario 1:

• Verified on a fresh profile there is no process started until opted in.
• Verified closing the browser and reopening doesn't list Crypto Wallet process
• Verified closing and reopening browser and visiting brave://wallet start the process
• Verified with process running, visiting Crypto Kitties doesn't show info bar and window.web3 is available in the tab
• Verified closing and relaunching browser and visiting Crypto Kitties shows info bar to start CW and reload the tab
• Verified setting process to always load works between relaunches

Scenario 2:

• Verified on a clean profile visiting CryptoKittes brings up info bar to setup Crypto
• Verified clicking on setup in info bar loads brave://wallet in new tab and shows opt-in page
• Verified after opt-in reloading the page provides window.web3 on the tab

Scenario 3:

• Verified installing MM and setting it as default doesn't start the process.
• Verified visiting CryptoKittes and setting MM as default also sets in setting
• Close and relaunch browser doesn't start the process
• Verified opting to CW doesn't change settings for default web3 provider

Scenario 4:

• Verified installing MM on a clean profile and visiting CryptoKitties shows info bar to choose default Dapp provider. Selecting CW sets its as default Web3 provider in settings
• Verified closing and relaunching the browser and visiting CryptoKitties shows info bar asking to restart the CW process

Scenario 5:

• Verified from an existing profile where CW is fully setup, upgrading shows no process for CW in task manager
• Verified visiting brave://wallet loads the extension and works fine

Scenario 6:

• Verified from an existing profile where CW is loaded but not setup, upgrading shows no process for CW in task manager
• Verified visiting brave://wallet shows opt-in page

Ran into #9821 for scenarios 5/6 which is fixed in #5591

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Test for #8121

• Verified on a clean profile visiting CryptoKitties shows info bar and selecting CW loads brave://wallet in a new tab and goes into opt-in state

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Test for #6595

• Verified having a window size of 400px by 400px and visiting brave://wallet loads the opt-in webUI which is responsive and scrollable

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Test for #8925

Verified there is no constant polling in the background when the process is not running

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Test for #8860

• Verified there is no Infura calls when the process is not running

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Test for #8120

• Verified visiting a Dapp automatically triggers info bar to setup CryptoWallet
• Verified if MM is installed and visiting a Dapp automatically triggers info bar to choose between CW and MM as default Dapp provider