Track file renamed/moved events

[mkondratek]

Fixes sourcegraph/jetbrains#2360.

This PR adds missing handling for onDidRenameFiles events.

Test plan

Note: It refers to JB Client.

Test Case 1: File Rename Operation

Setup:

project/
├── src/
│   └── foo.txt

Steps:

1. Open foo.txt in editor
2. Trigger Cody's "Edit Code" action
3. Verify code lenses appear with Accept/Reject buttons
4. Use Shift+F6 (or right click / Rename...) to rename foo.txt to bar.txt
5. Verify:
   • Code lenses remain visible after rename
   • Accept button successfully dismisses the lenses
   • New file path is correctly reflected

Test Case 2: File Move Operation

Setup:

project/
├── src/
│   └── foo.txt
└── dest/

Steps:

1. Open src/foo.txt in editor
2. Trigger Cody's "Edit Code" action
3. Verify code lenses appear with Accept/Reject buttons
4. Drag and drop foo.txt from src/ to dest/ folder
5. Verify:
   • Code lenses remain visible after move
   • Accept button successfully dismisses the lenses
   • File path updated to reflect new location

Expected Behavior

• Code lenses should remain functional after file operations
• Accept/Reject buttons should work properly
• File path references should be updated in Cody's internal state

[pkukielka]

Can you name that p0 meaningfully?

[mkondratek]

done

[pkukielka]

Do we really want to crash if they are the same?

[mkondratek]

Initially I put

    val uriBefore = uriFor(element.containingFile.virtualFile)

inside notifyAgent.

It turns out that at the moment we run that expression it evaluates to the same thing as uriAfter.

I do not see any other scenario for this assert to fail than a careless refactor. This assert is a safeguard.