feat: Use cupertino http and websocket implementation

[Vinzent03]

What kind of change does this PR introduce?

feature

What is the current behavior?

Uses the implementation from dart:io for http.Client and WebSocketChannel.

What is the new behavior?

Use the classes provided by cupertino_http.

Additional context

I do not own a mac, so I cannot test this. So we can hopefully find a person to verify this actually works on iOS and macOS.

close #147

[coveralls]

Pull Request Test Coverage Report for Build 14181154660

Details

• 9 of 20 (45.0%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.2%) to 75.265%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/supabase_flutter/lib/src/supabase.dart	3	5	60.0%
packages/supabase_flutter/lib/src/platform_http_io.dart	5	8	62.5%
packages/supabase/lib/src/realtime_client_options.dart	0	6	0.0%

Totals
Change from base Build 14080727348:	-0.2%
Covered Lines:	2845
Relevant Lines:	3780

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💛 - Coveralls

[grdsdev]

@Vinzent03 we should make sure we run CI also on macOS, and test the package at least in a iOS build, just saw that we don't to that.

I created an issue for tracking that, #1146 feel free to pick it if you want, otherwise I can work on it later.

[Vinzent03]

I'm pretty sure to verify the behavior of the cupertino http client we can't just run the existing ci on a macos build in ci. For iOS we need flutter integration tests to actually run them on a iOS simulator. For macOS I'm unsure if the cupertino http client works if we run widget tests or actually need integratino tests as well. So we would need to write many additional tests sa well.