feat(neon_http_client): add csrf interceptor

[Leptopoda]

The coverage is a bit different from the one reported by the flutter_test package, as they both use different coverage collectors.

Let's hope it won't be too off from the current one

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 29.74%. Comparing base (bc87322) to head (27c5f57).
Report is 14 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2300      +/-   ##
==========================================
+ Coverage   28.93%   29.74%   +0.81%     
==========================================
  Files         275      293      +18     
  Lines      108625   117527    +8902     
==========================================
+ Hits        31428    34960    +3532     
- Misses      77197    82567    +5370     

Flag	Coverage Δ		*Carryforward flag
cookie_store	100.00% <ø> (ø)		Carriedforward from bc87322
dynamite	31.08% <ø> (ø)		Carriedforward from bc87322
dynamite_end_to_end_test	60.96% <ø> (ø)		Carriedforward from bc87322
dynamite_runtime	85.40% <ø> (ø)		Carriedforward from bc87322
neon_dashboard	96.20% <ø> (ø)
neon_framework	45.85% <100.00%> (+0.02%)	⬆️
neon_http_client	93.95% <100.00%> (-6.05%)	⬇️
neon_notifications	100.00% <ø> (ø)
neon_talk	99.45% <ø> (+0.98%)	⬆️
nextcloud	26.64% <ø> (+1.17%)	⬆️
sort_box	90.90% <ø> (ø)		Carriedforward from bc87322

*This pull request uses carry forward flags. Click here to find out more.

Files	Coverage Δ
...n_framework/lib/src/blocs/login_check_account.dart	0.00% <ø> (ø)
...ework/lib/src/blocs/login_check_server_status.dart	0.00% <ø> (ø)
...kages/neon_framework/lib/src/blocs/login_flow.dart	0.00% <ø> (ø)
...ackages/neon_framework/lib/src/models/account.dart	91.66% <100.00%> (+0.14%)	⬆️
.../neon_framework/lib/src/utils/request_manager.dart	78.75% <100.00%> (+0.43%)	⬆️
..._client/lib/src/interceptors/csrf_interceptor.dart	100.00% <100.00%> (ø)
...ges/neon_http_client/lib/src/neon_http_client.dart	96.00% <100.00%> (-4.00%)	⬇️

... and 39 files with indirect coverage changes

[provokateurin]

Wasn't there a reason why we used flutter for running tests to collect coverage? I remember something wasn't working, but can't find the PR anymore.

[provokateurin]

Works as expected, but please check my last comment before merging.

[Leptopoda]

The way we collected the coverage before was broken and I think that you mainly wanted to unify both test cases.
#1858

what do you think?

[provokateurin]

Please break the tests on purpose to ensure the job will fail, since that was one of the problems we had before

[provokateurin]

Thanks for the test, seems like the CI will still fail properly 👍