refactor: applying lints suggestions

[h1376h]

No breaking changes and no changes in behavior.

(The comments starting with "// ignore" should be checked and fixed if needed)

[daadu]

any reason for adding all this lints?

[h1376h]

any reason for adding all this lints?

To reduce (future) possible errors, make code a bit more readable and improve the quality of code. These lints aren't some random ones, they are all suggested ones used in flutter repo and some other projects/packages and are just for having more control on what lints to use and what not to, instead of just using strong-mode like below

analyzer:
  strong-mode:
    implicit-casts: false

or using the very_good_analysis which has some lints with false positives.

Applying these changes also could probably accelerate development and make the code easier to contribute to.

Not letting compiler decide everything to be dynamic or not by helping it with some specifications, also may improve performance.