New way of habit status computation

[DanielRendox]

The idea of this PR

Currently, the app computes habit statuses and saves them to the database whenever GetRoutineStatusUseCase.invoke is called. While this makes it easier to figure out when the habit has some backlog or is completed ahead, this architecture has a huge pitfall. The saved data becomes outdated whenever the habit is completed or uncompleted. It's quite tricky to update every past calendar date every time it happens. Such a way of doing things may result in various bugs, unexpected behavior, and unclear code.
This PR provides a robust solution to this problem, while keeping the intended behavior. From now on, the database doesn't cash anything and keeps only necessary data such as the date mapped to how many times the habit was completed. The statuses are computed on the go. This functionality is located in the HabitComputeStatusUseCase and thoroughly tested in HabitComputeStatusUseCaseTest class.

How the main problem is solved

The problematic cases such as backlog and completing ahead are solved by computing the schedule deviation. computeScheduleDeviation function considers how many times the habit is due during the specified period and how many times it's completed during that period.

What changes are made

Implement pagination for routine calendar

Since the data is no longer cashed, it takes some time for it to be computed and shown on the screen. To maintain the native look and feel of the app, custom pagination was introduced for the calendar so that the data loading process seems to be instantaneous to the user. By pagination, I mean just loading habit statuses for future and past months even though they are not yet visible on the screen, not an official paging implementation.

Without pagination (left) and with pagination (right)

RoutineTracker_PR_6_changes_demonstration_pagination.mp4

Additional changes

• Adapted the rest of the project to meet the new way of habit status computation.
• Refactored Routine to Habit across the project because the term "routine" should represent an activity that is done in a fixed period of time. That could also be repeating tasks, events, and other things. So while the routine is still kept in many places where it implies such an abstract term, from now on things are called by their proper names.
• Fixed various minor bugs and performance issues.

[DanielRendox]

@CodiumAI-Agent /update_changelog

[CodiumAI-Agent]

Changelog updates:

2024-01-07

Changed

• Updated the core functionality of the app to compute habit statuses on the go instead of caching them in the database. This change improves the robustness and clarity of the code.
• Refactored 'Routine' to 'Habit' across the application for better semantics.
• Improved performance by computing each date in a separate coroutine and introduced pagination for the RoutineCalendarScreen.
• Updated the UI to support the insert/delete habit completion functionality.

Fixed

• Fixed various minor bugs and performance issues.

to commit the new content to the CHANGELOG.md file, please type:
'/update_changelog --pr_update_changelog.push_changelog_changes=true'