Enhancement: Upgrading the flutter version for easy setup

[RunTerror]

I will strive to align the existing dependencies and codebase to ensure compatibility with the latest Flutter version.

[RunTerror]

Null Safety Migration and Package Updates
Overview
This pull request documents the migration process to null safety and updates incompatible packages in the codebase. The goal is to enhance the project's stability, safety, and maintainability.

Changes Made
Dart Version Downgrade and Error Resolution:

Initially downgraded Dart version to 2.1.
Resolved all null safety-related errors in the codebase.
Pubspec Merging:

Merged the pubspec file after resolving compatibility issues.
Flutter Version Upgrade and Null Safety Activation:

Upgraded Flutter version.
Activated null safety using FVM.
Package Replacements:

Replaced incompatible packages with null-safe alternatives:
geolocator → flutter_geocoder_alternative
data_connection_checker → data_connection_checker_nulls
modal_progress_hud → modal_progress_hud_nsn

Updated project documentation to reflect changes made during null safety migration and package replacements.
Community Support:

[srockstech]

Hi, @RunTerror are you working on this issue? Or should I take it up? The repo has a lot of dependency issues as well due to null safety @cfsmp3

[RunTerror]

Hello @srockstech
I have successfully addressed and resolved issues related to Flutter, Dart, and their dependencies. I've submitted a pull request, and the maintainers will review it shortly.