* Fixes#11357
* Introduces validity parameter to TOTP generator function for future use elsewhere in the code base
* Fixes this in preview panel and TOTP dialog
* Disable actions to copy/show TOTP if the settings are invalid
* Show an error message on the TOTP setup dialog if the settings are invalid
* Show a TOTP icon with an x if the settings are invalid
Remove Unicode character U+FEFF ZERO WIDTH NO-BREAK SPACE from Weslly's
email address in a few places.
Not sure if this was done on purpose (anti-spam measure?), but it's not
consistently done anyway (e.g. wasn't the case in
src/gui/TotpDialog.cpp), so it seems cleanest to remove this.
* Fix#9847 - don't provide TOTP values if settings are blank or completely wrong
* Fix#6838 - don't reset the ui when creating a new entry and applying TOTP to it
* Move totp source into the core folder
