feat: expand and collapse all buttons

[massimopaganigh]

[massimopaganigh]

I'm honestly quite torn about what the best position for those two buttons might be.

[love-linger]

I think this PR is not suitable for SourceGit.

• Currently, there are only 5 groups (which is not many), and each group manages completely different things (Branches/Tags/Submodules/Worktrees).
• The layout of the entire left-sidebar has been manually optimized to avoid scrollbars appearing on the entire page, which would cause users to have to scroll the view first when wanting to close or open a certain group.
• The Expand/Collapse All operation actually has few application scenarios. Especially Expand All, I'm not sure in what situations users would need to expand all groups (as mentioned in the first point, these groups are not managing the same things, and in the second point the vertical space is too small that we need manually layout these groups). Moreover, even for Collapse All, I basically never use it because at least the LOCAL BRANCHES group will always be displayed by me.

[massimopaganigh]

@love-linger So maybe it would make sense to have a specific collapse option for Local Branches. I have several repositories that are structured in different subfolders (e.g., MILESTONE/TYPEOFCHANGE/#ISSUE/#SUBISSUE/...) and there is no real way to tidy them up by collapsing them all with a single click (as in Visual Studio).

[massimopaganigh]

Now that I think about it, it would also make sense to have a button to focus on the current branch (as in Visual Studio for the current document).

[love-linger]

Now that I think about it, it would also make sense to have a button to focus on the current branch (as in Visual Studio for the current document).

Try this button.