Add support for passing parameters onLoad

[frederikprijck]

• All new/changed/fixed functionality is covered by tests (or N/A)
• I have added documentation for all new/changed functionality (or N/A)

📋 Changes

Adds support for passing custom parameters to onLoad, which are used as global custom parameters in the underlying Auth0-SPA-JS SDK.

📎 References

Closes #345

🎯 Testing

Update the sample application here:

auth0Web.onLoad(parameters: {'foo': 'bar'}).then((final credentials) => setState(() {
  _output = credentials?.idToken ?? '';
  _isLoggedIn = credentials != null;
}));

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (253209a) 96.08% compared to head (cc8b662) 96.31%.
Report is 29 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #363      +/-   ##
============================================
+ Coverage     96.08%   96.31%   +0.22%     
============================================
  Files            97       98       +1     
  Lines          1611     1573      -38     
  Branches        331      328       -3     
============================================
- Hits           1548     1515      -33     
- Misses           49       50       +1     
+ Partials         14        8       -6     

Flag	Coverage Δ
auth0_flutter	100.00% <100.00%> (ø)
auth0_flutter_android	97.35% <ø> (+0.79%)	⬆️
auth0_flutter_ios	99.84% <ø> (ø)
auth0_flutter_platform_interface	87.03% <100.00%> (ø)

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[frederikprijck]

Needs #364 to fix the CI.