Upgrade polish language (I attach the corrected files)

[emillod]

Hello guys
I corrected the translation files. yuri please upload them to the 5.8 version
I have installed Sales & Advanced Pack so some labels can be from these packs.

Have a nice day.

[emillod]

Few updates
(I didn't update Admin.json)

[yuri]

Thanks. I will look into.

[yuri]

BTW, It's more convenient for us if fixes are made on poeditor site https://poeditor.com/join/project/gLDKZtUF4i

It's quite hard to separate needed labels from files generated in custom dir.

[emillod]

Next time i'll add changes through poeditor if you want me to.
Can you do something with files which i attached yesterday?

[yuri]

Not sure. I need to write separate script for this or pick items manually.