kpmcore updates

[Aurélien COUDERC]

Dear Team & Jonathan,

I’ve made some updates to kpmcore alongside the upgrade to the new upstream 
release 20.12.2 and would like to highlight 2 things:

- Now that the project is part of the official KDE apps release train, I’ve 
taken the liberty to move the package from « extras » to the « KDE » both for 
the Maintainer field and the GitLab repo.

- I’ve added a symbols file for libkpmcore10. I’m not so familiar with this so 
a cross check and feedback would be useful. In particular there are 2 
additional plugin libs that shouldn’t need symbols and I’ve excluded from 
dh_makeshlibs, but confirmation is welcome that this is the correct way.


Thanks & happy hacking !
--
Aurélien