Refactor: analyzer.go enhancements

[ohaval]

Hey kics team,

When working a bit with the analyzer.go file, I found some logical flows and tiny code improvements.
I wasn't sure if to open an issue for that, so I am just opening this small PR. Please let me know if there is something you need me to do.

In short:

• Fixed a weird check for an ansible vault using regex, and returning nothing if found (which is the opposite of what we would have been thinking should happen).
• A missing double quotes in a regex pattern.
• Changed regex expressions to use a backtick instead of " to avoid the double escape of the \ character.
• Removed a check at the start of each regex expression of \\s* as when using regex.Match, as it doesn't search only at the start of the searched string. Reference
• Small typo

[cxMiguelSilva]

Hi @ohaval,
Thank you so much for your amazing contribution!! 🚀
The proposed changes LGTM