feat(): implement purge cache issue

[diegofesanto]

What kind of change does this PR introduce?

feature

What is the current behavior?

Please link any relevant issues here.

What is the new behavior?

• implement purge cache for cdn parity(storage): expose purgeCache for buckets and single objects [from supabase-js] supabase-csharp#271

Additional context

• related parity(storage): expose purgeCache for buckets and single objects [from supabase-js] supabase-csharp#271
• related parity(storage): expose additional parameters in Download method [from supabase-js] supabase-csharp#233 (missing fetch parameter from here)

[diegofesanto]

@Tr00d could you check this pr, please?

I will put the FetchParameter on download method tomorrow that was missed

[Tr00d]

@diegofesanto Thanks a lot for contributing again.
I went through the PR and ended up making a few changes (made another PR to be merged in this one, here #52), rather than stacking review comments over here.
Here's my reasoning behind it:

• The FetchParameter/FetchCache types were modeled on the JS fetchParameters, but over there that's really just the abord signal. In .NET, it's the CancellationToken you already added, so I dropped those types. They were also serialized into the DELETE body, which the server doesn't expect.
• transformations defaults to purging everything on storage-js, so I changed the default to match (it was purging only transformations by default)
• I reworked the tests to check what's actually sent to the API: the path, absence of body, the transformations query and that cancellation is passed through.

None of this changes what you built, it's mostly aligning with JS the best we can and strengthening the tests.
Happy to talk though it, I mostly wanted to avoid a round of back-and-forth comments.

Cheers!

[diegofesanto]

@Tr00d thanks... I got it.

I merged your PR already...