Improve flatpak packaging of elisa to have baloo and mpris support

Summary:
fix configuration of sandbox permissions to allow mpris2 and Baloo usage

build tagib before kfilemetadata to use taglib extractor

build kdeclarative earlier since it has no dependencies on other elements

Test Plan: music is extracted from Baloo, mpris2 plasma applet works

Reviewers: apol, Flatpak

Reviewed By: apol, Flatpak

Differential Revision: https://phabricator.kde.org/D7295