Re-entrant SendKeystrokes (#20277)

Release Notes:

- Improved `workspace::SendKeystrokes` to support re-binding keys. For
example you can now do: `"x": ["workspace::SendKeystrokes", "\" _ x"]`
in vim mode to ensure that `x` does not clobber your clipboard.
- Improved key binding documentation

crates/vim/test_data/test_remap_recursion.json

@@ -0,0 +1,11 @@
+{"Exec":{"command":"noremap x \"_x"}}
+{"Exec":{"command":"map y 2x"}}
+{"Put":{"state":"ˇhello"}}
+{"Key":"d"}
+{"Key":"l"}
+{"Get":{"state":"ˇello","mode":"Normal"}}
+{"ReadRegister":{"name":"\"","value":"h"}}
+{"Key":"y"}
+{"Get":{"state":"ˇlo","mode":"Normal"}}
+{"ReadRegister":{"name":"\"","value":"h"}}
+{"Get":{"state":"ˇlo","mode":"Normal"}}