Deprecate `AbstractApi::get()`, `AbstractApi::post()`, `AbstractApi::put()` and `AbstractApi::delete()`

[Art4]

The methods AbstractApi::get(), AbstractApi::post(), AbstractApi::put() and AbstractApi::delete() are using AbstractApi::getContentTypeFromPath() to guess the content type from the path. It is preferable that the content type is provided directly by the methods in the API classes. This can be realized by using HttpClient::request() directly instead of using the method of AbstractApi. Therefore this methods could be deprecated.

• AbstractApi::get(): Deprecate AbstractApi::get() #381
• AbstractApi::post(): Deprecate AbstractApi::post() #383
• AbstractApi::put(): Deprecate AbstractApi::put() #388
• AbstractApi::delete(): Deprecate AbstractApi::delete() #392