Provide a generic to http get methods

[alallema]

Pull Request

What does this PR do?

Most of the methods had to use the jsonHandler after the call to the get method through the client. The purpose of this PR is to bypass this step to simplify the call to the get method via the client:

    public String[] getRankingRuleSettings(String uid) throws MeilisearchException {
        String urlPath = "/indexes/" + uid + "/settings/synonyms";
        return httpClient.jsonHandler.decode(httpClient.get(urlPath, String.class), String[].class);
    }

became

    public String[] getRankingRuleSettings(String uid) throws MeilisearchException {
        String urlPath = "/indexes/" + uid + "/settings/ranking-rules";
        return httpClient.get(urlPath, String[].class);
    }

Note:

This method still need a call to the decode method from jsonHandler

    public Map<String, String[]> getSynonymsSettings(String uid) throws MeilisearchException {
        String urlPath = "/indexes/" + uid + "/settings/synonyms";
        return httpClient.jsonHandler.decode(httpClient.get(urlPath, String.class), Map.class);
    }