Extend commit panel with branch operations (switch/rename/delete)

**Is your feature request related to a problem? Please describe.**
Lazygit's commit panel provides a clear visualization of the git graph, which is particularly helpful when working with complex branch structures.
During intensive branch cleanup sessions (involving rebasing and cherry-picking), I frequently need to switch between the commit panel and branch view to manage branches. This interrupts the workflow as I lose sight of the graph structure momentarily and need to keep branch names in mind while navigating between views. This becomes particularly challenging when working with multiple branches that need reorganizing.

**Describe the solution you'd like**
Since Lazygit already supports creating new branches from the commit panel, it would be helpful to have other branch operations available there as well. Specifically, being able to:
- Switch between branches
- Rename branches
- Delete branches
- Perform merges and rebases

Having these operations available directly where we can see the full branch structure would streamline complex git workflows.

**Describe alternatives you've considered**
Currently, I work with the standard approach of noting the branch name from the commit panel, switching to the branch view, finding the branch again, and performing the operation there. While this works, it interrupts the natural flow of working with the git graph, especially during intensive cleanup sessions.

**Additional context**
This enhancement would complement Lazygit's existing visualization capabilities. By bringing branch management directly to where the branches are visualized, it would make complex git workflows more efficient.