Feature: Added support for choosing the dual pane orientation

[0x5bfa]

Summary

• [x] Replace "OpenInSecondaryPane" with options to choose how the pane is split
• [x] Split vertical panes
• [x] Vertical splitter resizability
• [ ] Update tab actions visibility without needing to restart the app
• [ ] Do not override alignment direction settings
• [ ] Support changing split arrangement

Resolved / Related Issues

To prevent extra work, all changes to the Files codebase must link to an approved issue marked as Ready to build. Please insert the issue number following the hashtag with the issue number that this Pull Request resolves.

• Closes #12427

Steps used to test these changes

Stability is a top priority for Files and all changes are required to go through testing before being merged into the repo. Please include a list of steps that you used to test this PR.

1. Open Files app
2. Open the menu
3. Click 'Split pane' item

[0x5bfa]

@yaira2 because the text ShowTabActions has button and the control type of ToggleSwitch is button thus the text includes the control type name, the AXE test is failing. Could you consider text that doesn't include button?

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Two to-do is remaining.