Updated based off information on SwitchBrew.

Cleans up unused includes and trims off some dependencies on externals.

* get rid of boost::optional

* Remove optional references

* Use std::reference_wrapper for optional references

* Fix clang format

* Fix clang format part 2

* Adressed feedback

* Fix clang format and MacOS build

Gets rid of the need to call the getter and then check for null.

Nothing requires the shared owner ship here, so we can just return a
plain pointer.

Many of the Current<Thing> getters (as well as a few others) were
missing const qualified variants, which makes it a pain to retrieve
certain things from const qualified references to System.

* remove unnecessary if-statements

* Addressed feedback

Crypto revisions are hex numbers and this function only checks if the string is valid for stoul in base 16, so it should be isxdigit.

Prevents nullptr bug when trying to dump the RomFS of an NSP resulting from secondary_loader not being initialized.

Avoids the need to put the scaling parameters all over the place for the
common case. The only other time scaling is done is to generate the
smaller 48x48 image, so this is fine.

Avoids the need to duplicate this all over the place, and makes it
translator-friendly across the board.

We should display an error to the user if setting a user image for an
account fails, rather than continuing onwards.

We already ignore them on listing devices. We should do the same when selecting devices. This fix a crash when opening a specific device while there is a null device in the list

Nothing from this enum is intended to be used outside of this function.

This retrieves:

if (curr_thread == handle_thread) {
   result = total_thread_ticks + (hardware_tick_count - last_context_switch_ticks);
} else if (curr_thread == handle_thread && sub_id == current_core_index) {
   result = hardware_tick_count - last_context_switch_ticks;
}