"Time Until Event" is low-precision until 1 hour prior; make it adjustable

[cwotta]

Is your feature request related to a problem? Please describe. The current "Time Until [Calendar] Event" is low-precision (rounded to the nearest [e.g.,] 1 hour ) until just 1 hour prior to the event. This rounding has caused several "oh no!" moments.

Describe the solution you'd like I'd like the "time prior to the event at which the precision of "Time Until Event" increases" to be configurable (i.e., not hard-coded to 1 hour prior)

Describe alternatives you've considered N/A

Additional context I have tried to create a branch (not yet uploaded) adding this adjustable menu option. However, I do not have Android dev experience nor Android Studio running to test. Instead, I mirrored other related menu items to add this change.

I do not intend to create (much :) ) more work for the main developers; but if you'd like me to upload my changes, let me know a branch name to create. Changes (additions) were made to: strings.xml, MainViewModel.kt, CalendarFragment.kt, SettingsStringHelper.kt, fragment_tab_calendar.xml, and Preferences.kt

This may create a minor merge conflict with the azuo-patch-develop branch in two lines in SettingsStringHelper.kt, but I incorporated those changes into my file.