fix(submit): trim new word before using

[filipdutescu]

Motivation

Trim the new word of leading and ending spaces before using it to rename. This should prevent padding from being used in the final name, as well as making it a bit more logic and consistent with most IDEs.

Fixes: GH-119

Proposed changes

• trim new_word spaces on submit (as seen in this StackOverflow question)
• radd a test case to validate the change

Test plan

Existing tests are updated and a new test case is added in lua/tests/rename_close_spec.lua.