Remove FXIOS-9085 Inactive tab legacy code

[lmarceau]

:scroll: Tickets

Jira ticket Github issue

:bulb: Description

Removing some part of the Legacy inactive tab code. Still some related code to be removed, this is one step in that direction before I get to the most tangled part.

Realized by looking in this code that we haven't move the legacy inactive tab telemetry to the new code base it seems. So events like inactiveTabSwipeClose, inactiveTabShown, inactiveTabCloseAllButton and openInactiveTab amongst other things aren't used anymore. I asked Andy if we want to migrate those, if so I'll create a task for this so we implement them back (otherwise I'll delete them).

:pencil: Checklist

You have to check all boxes before merging

• [X] Filled in the above information (tickets numbers and description of your work)
• [X] Updated the PR name to follow our PR naming guidelines
• [X] Wrote unit tests and/or ensured the tests suite is passing
• [ ] When working on UI, I checked and implemented accessibility (minimum Dynamic Text and VoiceOver)
• [ ] If needed, I updated documentation / comments for complex code and public methods
• [ ] If needed, added a backport comment (example @Mergifyio backport release/v120)

[mobiletest-ci-bot]

	Warnings
:warning:	Pull Request size seems relatively large. If this Pull Request contains multiple changes, please split each into separate PR will helps faster, easier review. Consider using epic branches for work that would affect main.

	Messages
:book:	Project coverage: 32.5%
:book:	Edited 4 files
:book:	Created 0 files

Client.app: Coverage: 31.32

File	Coverage
TopTabsViewController.swift	0.0%	⚠️
LegacyInactiveTabViewModel.swift	0.0%	⚠️
TabDisplayManager.swift	0.0%	⚠️

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