More text strings and some fixes in new lines code

Fixed some new line commands and added more text strings to the translation file.

# DONT Merge this pull request.

There is a Syntax error on

self.layout.addWidget(QLabel(_("Your transaction has been sent.")+"\n"+_("Please enter a label for this transaction for future reference."))


Update:
# All the other changes works perfectly

I will send a new PR with the good changes