Update metadatacheck to fit v5.1

[poeschlr]

klc update KiCad/kicad-website#446

[evanshultz]

No real reason to keep a counter since the result ultimately goes to a Boolean. But I guess in the future it could be handy and it works now too.

[poeschlr]

All other scripts use counters

[evanshultz]

I assume at KiCad/kicad-website#446 (comment) you are referring to this script update?

check_lib_file requires at least four pieces of documentation in the lib file. Isn't that wrong? Don't we want F4 to always be blank, and we also accept F3 to be blank for generic symbols that only have a bunch of FP filters? Maybe I didn't quite understand this.

[poeschlr]

I now ran the new script and old script on the current master branch of the symbol lib (Limited to the rules that i changed). There is not really a difference in the reports other than what is expected from combining the rules (S6.3 changed to S6.2, detailed messages changed and if both s6.3 and S6.2 is violated then they are of course under the same header which makes diff think something was added in the original)
The logs i created in this process:
before_change_1.txt
after_change_1.txt