Make max results for Label Detection configurable

Thanks for the patch!

1. +++ b/src/Form/GoogleVisionSettingsForm.php
   @@ -50,10 +50,79 @@ class GoogleVisionSettingsForm extends ConfigFormBase {
   +    $form['max_results_fieldset'] = [
   

   change form key to 'max_results'

2. +++ b/src/Form/GoogleVisionSettingsForm.php
   @@ -50,10 +50,79 @@ class GoogleVisionSettingsForm extends ConfigFormBase {
   +    $form['max_results_fieldset']['max_results_label_detection'] = [
   

   don't append the max_results before with every form key.

   Make it simple 'label_detection'
   Address at other places as well.

Hi,
I would like to focus light on some points:
1. Only the Label Detection feature of the Google Vision API should be configurable. These are related to taxonomy tagging, hence, I agree to the point that it should be in the hands of the user.

However, other features need not be configurable, as it would be of no use. Here is why?
1. Landmark, Logo, Optical Character Detection have been used to fill the Alt Text attribute of the image file. So, IMHO, its of no use to leave it on the end user.
2. Safe Search detection feature is used to detect and avoid any explicit contents in images being uploaded. Hence, no use of making it configurable to have many values. It does not actually need any manipulation on the hands of the user.
3. Same is the case of User Emotion Detection.
4. As far as Image Properties is concerned, the image would have only one dominant color, either Red, Green or Blue or in the worst case, all the three (if the image is black and white).

We have hard coded the 'maxResults' with those values, as they would suffice our demand and requirements to use the features.

Here, I am uploading the new patch with necessary changes to reflect the configuration. Also, I have added and updated the tests to verify whether the value is configurable or not.

leaving this open for the thoughts of eugene on this, what he thinks about #10

I prefer the solution of Arpit. His explanation in #10 sounds pretty logical.

Committed.