Fix: Format Tags in YAML Should Only Match tag or tags YAML Value.

[pjkaufman]

Fixes #1155

There was an issue where Format Tags in YAML was matching on more than just the value for the tag or tags key if that key was directly or shortly thereafter followed by a value that had a # in it. Updating the regex to better match how regex values are identified elsewhere seems to fix this issue.

Changes Made:

• Added a UT for the scenario in question
• Updated regex to match more closely what is done to get a YAML key's value elsewhere