more intelligent automatic selection of compiled translations

currently, we have the following situation:

• the qt build compiles all available TS files, including the outdated and low-quality ones
• the creator build compiles a manually specified list which is permanently outdated

to solve the problem, the check-ts target was introduced to automatically update the list of completed translations. however, it only makes sense to run it shortly before a release. the remaining time (on development branches), all available translations should be compiled. or alternatively, none of them, as they'll be outdated most of the time anyway.