Add possibility to provide a generic to http methods

[bidoubiwa]

Description
Every method that makes an HTTP request also decode the JSON from that request inside its method.

Example:

meilisearch-java/src/main/java/com/meilisearch/sdk/TasksHandler.java

Lines 48 to 51 in 04244fa

	public Task[] getTasks(String indexUid) throws Exception {
	String urlPath = "/indexes/" + indexUid + "/tasks";
	return this.gson.fromJson(this.meilisearchHttpRequest.get(urlPath), Task[].class);
	}

An alternative to that would be to use this.gson.fromJson inside the HTTP methods and provide the type decoding type with a generic. We would avoid a lot of code duplication by doing so.

By adding a generic to this function for example:

meilisearch-java/src/main/java/com/meilisearch/sdk/MeiliSearchHttpRequest.java

Lines 51 to 53 in 04244fa

	public String get(String api) throws Exception, MeiliSearchApiException {
	return this.get(api, "");
	}

Basic example

pseudo code:

   public String get<T>(String api) throws Exception, MeiliSearchApiException {
        return this.gson.fromJson((this.get(api, ""), T);
    }

Which change the first example to the following:

 public Task[] getTasks(String indexUid) throws Exception { 
     String urlPath = "/indexes/" + indexUid + "/tasks"; 
     return this.meilisearchHttpRequest.get<Task[]>(urlPath);
 } 

Possible issue

This method does not use the fromJson method:

meilisearch-java/src/main/java/com/meilisearch/sdk/Search.java

Lines 28 to 32 in 04244fa

	String rawSearch(String uid, String q) throws Exception {
	String requestQuery = "/indexes/" + uid + "/search";
	SearchRequest sr = new SearchRequest(q);
	return meilisearchHttpRequest.post(requestQuery, sr.getQuery());
	}

[alallema]

Closed by #466