FIXES #1064

 - The language and BCP need to be in-sync
 - Existing code was inconsistent in setting things, which is why
   you could get through the locale page without setting a locale
   (at all) or it would keep English in spite of picking Germand on
   the welcome page.
 - Patch tests to use that API.

 - This shows that one constructor isn't doing it right.

 - Allow split-setting of the language and formats
 - Test new constructors
 - Since fromLanguageAndLocation can handle empty localeGen
   lists just fine, skip all the weird checks that return
   invalid guessed locale configurations.

 - Replace createDefault() with a constructor that takes a
   locale name; use it with en_US.UTF-8 in those places where
   createDefault was previously used.

 - When finding the gettext path, the debug output was very
   chatty and didn't include an indication that it was looking
   for translations.

 - use debugging to be a little more chatty
 - when changing the system language on the locale page,
   the global locale setting should change, too.

 - code formatting
 - provide an operator << for debugging TZ widget

 - When testing and running not-as-root, only call the timedatectl
   when the settings actually change; this reduces the number of
   times kauth pops up.

 - Dangerout since we're mounting things inside that tempdir,
   and then doing a "weak" unmount

This fixes the crash by calling the model-reset first, then
refreshing. Previously, the destructors that do the work
were still being called in the wrong order.

FIXES #1019

 - The ResetHelper only finalized changes to the module on
   destruction, but calls to refresh() assumed it was already
   done. This leads to crashes when refresh() uses an intermediate
   state of the model.

Introduce extra helpers, and rename refresh() to avoid calling the
old implementation from any code. The new helper just creates and
destroys a ResetHelper, before creating and destroying an object
that calls the new refreshAfterModelChange().

FIXES #1019

 - document new variable from the CMake module
 - use it in libcalamaresui to simplify #include'ing the
   header for the "all" extension.

Suggested by Denis Proskurin.

Suggested by Denis Proskurin.

Suggested by Denis Proskurin.

do not set boot flag on ESP (thanks @philmmanjaro for testing)

do not set active flags on the to-be ESP (thanks @philmmanjaro for testing)

grubcfg: Only try to decrypt disk that /boot is on (thanks @philmmanjaro for testing)

ESP == boot. at best this is duplicated information, at worst kpmcore may
implode if you try to set a boot flag since that is technically an MBR
type flag and means nothing within the context of GPT where ESP is the flag
to set.

having ESP as active flag AND then trying to set ESP means nothing is
set since kpmcore will think ESP is already set (it is listed as active
after all). this ultimately meant that nothing was set since there was
no delta between the requested flags and the already active flags.