Refactor Settings Activity / ViewModel to use single view state

[xizzhu]

Essentially part of #233, which is too big to manage.

[codecov-commenter]

Codecov Report

Merging #248 (cd2d575) into master (38ae967) will increase coverage by 0.65%.
The diff coverage is 55.36%.

@@            Coverage Diff             @@
##           master     #248      +/-   ##
==========================================
+ Coverage   60.70%   61.36%   +0.65%     
==========================================
  Files         121      121              
  Lines        5242     5391     +149     
  Branches      679      708      +29     
==========================================
+ Hits         3182     3308     +126     
- Misses       1986     2011      +25     
+ Partials       74       72       -2     

Impacted Files	Coverage Δ
...android/joshua/annotated/AnnotatedVerseActivity.kt	0.00% <0.00%> (ø)
...e/xizzhu/android/joshua/reading/ReadingActivity.kt	0.00% <0.00%> (ø)
.../me/xizzhu/android/joshua/search/SearchActivity.kt	0.00% <0.00%> (ø)
...xizzhu/android/joshua/settings/SettingsActivity.kt	0.00% <0.00%> (ø)
...ndroid/joshua/strongnumber/StrongNumberActivity.kt	0.00% <0.00%> (ø)
.../main/kotlin/me/xizzhu/android/joshua/ui/Dialog.kt	0.00% <0.00%> (ø)
...rc/main/kotlin/me/xizzhu/android/joshua/ui/View.kt	15.55% <0.00%> (-3.37%)	⬇️
...n/kotlin/me/xizzhu/android/joshua/utils/Context.kt	65.51% <62.50%> (+1.51%)	⬆️
...izzhu/android/joshua/settings/SettingsViewModel.kt	91.34% <90.72%> (+6.90%)	⬆️
...n/me/xizzhu/android/joshua/core/SettingsManager.kt	84.21% <100.00%> (+11.48%)	⬆️
... and 4 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more