Change string into another sentence.

Currently: https://plugins.trac.ww.wp.xz.cn/browser/booking-package/trunk/index.php#L5309

For the date when a booking is received… It says: “Reception date”. Now, the issue is that in a lot of languages “Reception” means a lot different things. EG, in my native language of Dutch it can even mean “the date when the reception with drinks and snacks takes place.”

I honestly think it’s the safest to change this string to “Submission date” or “Entry date” or something along those lines to avoid mistranslations.