Make webif compression optional

= Reason for enhancement Currently webif compression is always enabled. While it reduces size of binary ~100-250kB, there are some better options:

• use UPX with binary, even the fastest compression gives much better results
• some receivers have filesystem compression - even bigger binary would use less space, because it can be compressed better
• in other cases - as of 2024 - saving 300kB of flash space imho does not really make sense. Anyway I left compression enabled by default.

= Possible impacts on other features None