feat: workspace lookup before opening from CLI

[gitPhate]

This PR improves the command line repo opening by looking up the repository among the ones already opened in all workspaces.
Tests done on win 11, with 3 workspaces configured:

1. Program closed → CLI-open repo in a different workspace — works
2. Program closed → CLI-open a different repo already in the same workspace — works
3. Program open → CLI-open repo in a different workspace — works
4. Program open → CLI-open a different repo in the same workspace — works
5. Multi-tab target workspace — CLI-open correctly focused the right tab within the target workspace, not just whatever tab was last active there
6. Bare repository, using the test repo at C:\Development\test-bare-repo.git — switched workspace correctly, tested both closed and already-open app states
7. Case-insensitive path (CLI invoked with a lowercase path against a repo added with different casing) — matched correctly
8. Persistence after CLI switch — relaunching normally afterward opens into the workspace the CLI switch left you in, as expected