Update dependencies and fix typos

[ThexXTURBOXx]

This PR updates flutter_secure_storage and flutter_web_auth_2 without breaking changes for the user.
Also, all the new parameters for flutter_web_auth_2 are supported now.

If you want to use these changes right now, you can specify the following dependency_override inside your pubspec.yaml:

dependency_overrides:
  oauth2_client:
    git:
      url: https://github.com/ThexXTURBOXx/oauth2_client.git

Fixes #172
Closes #173
Closes #176
Closes #177

[codecov-commenter]

Codecov Report

Merging #178 (407baa6) into master (36f7e70) will not change coverage.
The diff coverage is 0.00%.

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@@           Coverage Diff           @@
##           master     #178   +/-   ##
=======================================
  Coverage   88.34%   88.34%           
=======================================
  Files          11       11           
  Lines         446      446           
=======================================
  Hits          394      394           
  Misses         52       52           

Files	Coverage Δ
lib/src/io_web_auth.dart	25.00% <0.00%> (ø)

[ThexXTURBOXx]

I have also bumped the SDK constraints and fixed more typos now :)

[natebgurutech]

I ran into an issue getting this package to work on Windows, I found after attaching the debugger in Visual Studio to the running process that a .cpp file in flutter_secure_storage was aborting and crashing the app.

I overrode the dependency in pubspec.yaml to the latest version of flutter_secure_storage like so:

dependency_overrides:
  flutter_secure_storage: 9.0.0

and it fixed the issue.

I see that this pull request also has this fix. Is it possible to get it pulled into the main repo?

[ThexXTURBOXx]

@natebgurutech If you want to use my fork, you can also use it directly like this until this PR is merged and properly published:

dependency_overrides:
  oauth2_client:
    git:
      url: https://github.com/ThexXTURBOXx/oauth2_client.git

[btrautmann]

@okrad any chance we can get this merged?

[btrautmann]

My comment above can be ignored 😅 I ended up writing my own client in combination with UrlLauncher that achieves the same but has way more graceful handling of errors, etc. than oauth2_client. Appreciate this PR though as I've used it for the past 6 months or so!