Refactor all pre-compiled regexp to package level vars

Addresses #8057

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>
@estesp I would love to see standardization around using backticks ` instead of double quotes ". That way there is no need to escape with \ and the regex is easier to read. I understand this PR is about moving the regexes up to package level vars, but if you think you could make this little change I would love that :). If you do that, builder/support.go would also need the update. Let me know what you think.