[QA] tests for exceeding thumbnails max_input configs

[saw-jan]

Bug report: #10589

Required envs: (change values if necessary)

THUMBNAILS_MAX_INPUT_IMAGE_FILE_SIZE=1MB
THUMBNAILS_MAX_INPUT_WIDTH=100
THUMBNAILS_MAX_INPUT_HEIGHT=100

Test cases:

Pre-conditions:

• run ocis with above thumbnails configs
• upload image that exceeds one or more of the above values

Test:

• download the 32x32 thumbnail of that image
• try to download the 200x200 (exceeding config value) thumbnail of that image
  • assert 403 Forbidden
  • assert response body

    <?xml version="1.0" encoding="UTF-8"?>
    <d:error xmlns:d="DAV" xmlns:s="http://sabredav.org/ns">
      <s:exception></s:exception>
      <s:message>thumbnails: image is too large</s:message>
    </d:error>

• upload a .txt file and download thumbnail