PAINTROID-634 : Add Eraser tool

[bakicelebi]

PAINTROID-634
PAINTROID-533
PAINTROID-646

New Features and Enhancements

• Eraser Tool: Added an eraser tool that functions similarly to the brush tool but utilizes a different BlendMode.
• Constant Identifier Names Analysis: Added a new analysis option constant_identifier_names which is set to false to stay consistent with Paintroid-Kotlin.
• Clipboard Icon: Copied the clipboard icon asset from Paintroid-Kotlin.
• BlendMode and StrokeJoin Serialization: Expanded the paint serializer to include support for BlendMode and strokeJoin properties.
• ToolType Differentiation: Assigned a ToolType to each tool, enhancing tool management and identification.
• ModalBottomSheet for Tools: Implemented a ModalBottomSheet that displays a list of available tools.
• Navigation Enhancement: Added the BottomNavBar functionality to highlight the active tool.
• Toast Package Update: Replaced the toast package with this package for better toast notifications.
• Integration Test Improvements: Changed integration testing through the addition of utility functions and the reorganization of existing tests.

Refactorings and Bug Fixes

• Component Renaming: Renamed the component "BottomControlNavigationBar" to "BottomNavBar" for consistency and clarity.
• Background and PaintingLayer Refactoring: Refactored the BackgroundLayer and PaintingLayer widgets for improved readability.
• PaintSerializer Optimization: Optimized the PaintSerializer class.
• Image Saving Improvement: Reworked the image-saving mechanism to fix JPG transparency issues that arose when using the eraser tool.
• Bug Fix: Addressed a bug where strokes were saved with incorrect stroke widths in projects/images.
• API Permission Handling: Fixed permission issues for API versions greater than 28.

Checklist

• Include the name of the Jira ticket in the PR’s title
• Include a summary of the changes plus the relevant context
• Choose the proper base branch (develop)
• Confirm that the changes follow the project’s coding guidelines
• Verify that the changes generate no compiler or linter warnings
• Perform a self-review of the changes
• Verify to commit no other files than the intentionally changed ones
• Include reasonable and readable tests verifying the added or changed behavior
• Confirm that new and existing unit tests pass locally
• Check that the commits’ message style matches the project’s guideline
• Stick to the project’s gitflow workflow
• Verify that your changes do not have any conflicts with the base branch
• After the PR, verify that all CI checks have passed
• Post a message in the #paintroid Slack channel and ask for a code reviewer

[juliajulie95]

I would write the whole name like you did with the others
backgroundPicture
backgroundImage
Also those 2 are synonyms, maybe specify what makes them different in the name

[bakicelebi]

Refactored the function, it should be more readable now

[juliajulie95]

Added some comments, looks good to me though!