Plugin Directory: Loosen slug/name usage

[Ipstenu]

By altering some slugs to only check for trademarks in the MIDDLE of the slug, we allow people to submit plugins with names like "My cool plugin FOR trademark" - this is not going to work for all trademarks or terms, as their owners have requested a secession on full use. Also some we just need to avoid.

This is done by including a hyphen at the end of the term for those terms that can be used, but only at the end. That said, this is still an imperfect check, as it would catch "Blah blah for Google Maps" - a better long term solution will be needed, but this will get us to a better place. More restrictive is easier to fix since we can edit slugs, and it lessens the possibility of infringement.

We may need to split this out into trademarks and restricted. It's hard to explain why you can use 'blah blah FOR X' but not for all trademarks, just because some owners are more restrictive than others.

[SergeyBiryukov]

In 9102:

Plugin Directory: Loosen the check for trademarked slugs to allow using some terms of less restrictive owners to be used at the end of a slug.

Props Ipstenu.
Fixes #4676.