[BUG] Breaking bash case statement when saving result to a var

Amber breaks bash case syntax by adding brackets.

Example:
```
let result = unsafe $case "{text}" in
*"{phrase}"*\)
echo 1
;;
esac$
```

evals to:
```
__AMBER_VAL_0=$(case "abc" in
*"a"*)
echo 1
;;
esac);
__AS=$?;
__0_result="${__AMBER_VAL_0}"
```