[Feature] „Go to current document” in solution explorer

**Is your feature request related to a problem? Please describe.**
If you have a lot of documents opened, it is annoying to manually find the item in the solution explorer list.

**Describe the solution you'd like**
There should be a button „go to current document” in solution explorer.

**Additional context**
Bonus points if it possible to add the button in the „solution explorer” title bar (not sure how hard it would be).

Start by locating the solution explorer UI and how the currently open document is tracked. Check the existing solution explorer actions and title-bar layout before deciding where the command belongs. Done means a button can locate and select the current document, with title-bar placement treated as an optional enhancement.

Written by the indexing model from the issue text.