Generate rules automatically using github search API

[AyanSinhaMahapatra]

There are a lot of new licenses added and it is nice if we have a script to automate searching for rules for these licenses and adding these as rules.

For example in #4478 we had the following licenses added:
new_licenses.txt

The steps roughly are:

• Get the new licenses using synclic (license sync) scripts
• Get the new license keys (using GitPython: read changed files)
• Get the license names to search for (might have to search without version numbers too)
• Use github search API to search for license occurances (remove scancode/licensedb related search results)
• run license detection to see if we detect these correctly
• if license not detected correctly add as rules:

I have this working roughly, but this needs some improvements and the new license matcher. Will add the script soon.