add support for multiple preference types

[ZvonimirMedak]

Summary

Based on #32 I have added support for multiple preference types in SwiftUI

Changes

Type

• Feature: This pull request introduces a new feature.
• Bug fix: This pull request fixes a bug.
• Refactor: This pull request refactors existing code.
• Documentation: This pull request updates documentation.
• Other: This pull request makes other changes.

Additional information

• This pull request introduces a breaking change.

Description

This PR adds a PreferenceItem protocol which will be used on the Preferences screen.
Added the support for Text, Int, Float, Double, and picker (CustomStringConvertible + RawRepresentable).
There are also validators which can be used with those items.
The UI has also been updated to have a description label below the item which will show the description or the last error message from the Validator

Checklist

• I have performed a self-review of my own code.
• I have tested my changes, including edge cases.
• I have added necessary tests for the changes introduced (if applicable).
• I have updated the documentation to reflect my changes (if applicable).

Additional notes

The ToggleToolItem kept the same name due to it already existing in Sentinel, maybe we can create a type alias which would be PreferenceBoolItem, and then we could use both without creating a breaking change.