Search by catalog number in user's collection: add a prototype

[php-coder]

This is part of #673

Acceptance criteria:

• add a checkbox to Search series form on the main page
• checkbox should have a title In my collection (or В моей коллекции in Russian)
• checkbox shouldn't be selected by default
• add feature toggle SEARCH_IN_COLLECTION to the Features file
• new feature should be disabled by default
• checkbox should be visible only when new feature is active AND user is authenticated (use Spring Security attributes for Thymeleaf)

[mukeshk]

Does this look good ?

[php-coder]

Yeah, something like this. Let's put checkbox first, before title and remove a colon also.