imperative: Add state match alias for Python/Rust (talonhub#1440)

In Python and Rust, we've implemented `code_state_switch()` to insert
the `match` keyword. Give it that name too.

lang/tags/imperative.talon

@@ -8,7 +8,7 @@ state while: user.code_state_while()
 state loop: user.code_state_infinite_loop()
 state for: user.code_state_for()
 state for in: user.code_state_for_each()
-state switch: user.code_state_switch()
+state (switch | match): user.code_state_switch()
 state case: user.code_state_case()
 state do: user.code_state_do()
 state goto: user.code_state_go_to()