Allow variable rename that's in use

# Expected Behavior

Renaming a variable throughout an entire sequence should be possible. Like search'n'replace in a text editor.

# Actual Behavior

If I understand…

https://github.com/FarmBot/Farmbot-Web-App/blob/a5cfa75465d368acbae90e60a26709be6fc260d9/frontend/sequences/locals_list/variable_form.tsx#L353-L359

…correctly, it's currently necessary to remove a variable from a sequence before renaming it?

However, it would IMHO be helpful to directly rename it in all sequence elements at once, for example to avoid errors in re-adding it.