[E2E] Install Firefox extension from dist folder

[PeterYinusa]

Explanation

• Update Selenium Webdriver from v4.1.0 to v4.3.1, to be able to install unpacked addons at runtime in FF, which was introduced in v4.2.0
• Updated the framework to install the extension in Firefox from the dist folder similar to chrome, rather than using the zip in the build folder.
• Removed some code from the Snaps tests which became redundant after the above change

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[metamaskbot]

Builds ready [296b5b2]

• builds: chrome, firefox, opera
• builds (beta): chrome, firefox, opera
• builds (flask): chrome, firefox, opera
• build viz: Build System
• code coverage: Report
• storybook: Storybook
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • content-script: 0
  • contentscript: contentscript
  • disable-console: disable-console
  • inpage: inpage
  • policy-load: policy-load
  • sentry-install: sentry-install
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

Page Load Metrics (1827 ± 92 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	93	166	115	18	9
		domContentLoaded	1634	2338	1812	176	84
		load	1634	2361	1827	191	92
		domInteractive	1634	2338	1812	176	84