fix: Provide client scopes as a space delimited string instead of a json list

[Elleo]

1. Description

The currently existing behaviour sends scopes as a json encoded list (e.g. ["read", "write", "follow"]), however, Mastodon expects a space-separated string ("read write follow"). This PR corrects that behaviour so that apps are assigned the correct scopes by the Mastodon server.

1.1. Checklist

• The title of my PR starts with a Conventional Commit prefix (fix:, feat:, docs: etc).
• I have read the Contributor Guide and followed the process outlined for submitting PRs.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples.

1.2. Breaking Change

• Yes, this is a breaking change.
• No, this is not a breaking change.

1.3. Related Issues

Fixes #78

[github-actions]

Thanks for your contribution! :)

[codecov-commenter]

Codecov Report

Merging #79 (8e80bff) into main (53eca1b) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #79   +/-   ##
=======================================
  Coverage   69.35%   69.35%           
=======================================
  Files          85       85           
  Lines         832      832           
=======================================
  Hits          577      577           
  Misses        255      255           

Impacted Files	Coverage Δ
lib/src/service/v1/apps/apps_v1_service.dart	100.00% <100.00%> (ø)

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[myConsciousness]

@Elleo , Thanks for your contribution! :)

[myConsciousness]

bors merge

[myConsciousness]

@all-contributors please add @Elleo for code, bug, test

[allcontributors]

@myConsciousness

I've put up a pull request to add @Elleo! 🎉

[bors]

Build succeeded:

• analyzer
• test