Remove timeout logic from ReadRaw functions and add ReadRawWithContext

[averche]

Removing the timeout logic from raw-response functions and adding documentation comments. The following functions are affected:

• ReadRaw
• ReadRawWithContext (newly added)
• ReadRawWithData
• ReadRawWithDataWithContext

The previous logic of using ctx, _ = c.c.withConfiguredTimeout(ctx) could cause a potential context leak:

Failing to call the CancelFunc leaks the child and its children until the parent is canceled or the timer fires. The go vet tool checks that CancelFuncs are used on all control-flow paths.

Cancelling the context would have caused more issues since the context would be cancelled before the request body is closed.

Resolves: #18658

[cipherboy]

This makes sense to me, thanks @averche for taking this on!

[cipherboy]

Very nice! Thank you!