feat: redesign login process

[adil192]

Early draft PR.

Todo:

• Login with Saber nc
• Login with third party nc
• Encryption password page
• Use profile page as the last page
• Prefs.username.value != null is used throughout the code to check if the user is logged in. Change this to also check Prefs.encPassword.value via a Prefs.loggedIn getter
• Add the FAQs back in, update them, or delete them
• Make everything translatable
• Delete LoginInputGroup
• Handle app passwords differently to regular passwords

[codecov]

Codecov Report

Attention: Patch coverage is 3.22581% with 420 lines in your changes are missing coverage. Please review.

Project coverage is 36.01%. Comparing base (c996b39) to head (34e7ed0).

Files	Patch %	Lines
lib/components/nextcloud/nc_login_step.dart	0.00%	139 Missing ⚠️
lib/components/nextcloud/enc_login_step.dart	0.00%	76 Missing ⚠️
lib/components/nextcloud/done_login_step.dart	0.00%	66 Missing ⚠️
lib/pages/user/login.dart	0.00%	46 Missing ⚠️
lib/data/nextcloud/login_flow.dart	0.00%	36 Missing ⚠️
lib/components/misc/faq.dart	0.00%	17 Missing ⚠️
lib/components/settings/nextcloud_profile.dart	0.00%	15 Missing ⚠️
lib/data/nextcloud/readable_bytes.dart	0.00%	14 Missing ⚠️
lib/data/nextcloud/nextcloud_client_extension.dart	75.00%	2 Missing ⚠️
lib/components/home/delete_folder_button.dart	0.00%	1 Missing ⚠️
... and 8 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1246      +/-   ##
==========================================
- Coverage   36.74%   36.01%   -0.74%     
==========================================
  Files         112      114       +2     
  Lines        8817     9000     +183     
==========================================
+ Hits         3240     3241       +1     
- Misses       5577     5759     +182     

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