Migrated methods which used `js::jsapi::JSContext` and `script_runtime::JSContext` to use `js::context::JSContext`.
Also imported methods from `js::rust::wrappers2` in place of the ones from `js::rust::wrappers` and `js::jsapi`.
Method `internal_warn` has not been migrated to use `&mut JSContext` in this commit.
Signed-off-by: Steve Sharon Sam <157230657+SteveSharonSam@users.noreply.github.com>

Signed-off-by: Steve Sharon Sam <157230657+SteveSharonSam@users.noreply.github.com>

Resolved comments by reviewer:
-Removing unwanted variables.
-Importing `js::rust::wrappers2` functions
-Changes to how `cx` is taken inside `rooted!` macro.
Signed-off-by: Steve Sharon Sam <157230657+SteveSharonSam@users.noreply.github.com>

Removed some unsafe blocks as they were not required and also removed unsafe from some functions.
Signed-off-by: Steve Sharon Sam <157230657+SteveSharonSam@users.noreply.github.com>