Request parameters are lost after changing a language

[php-coder]

How to reproduce:

• open index page
• try to search stamps by number 99
• on page with results change a language

Expected result:

• language was changed and search results remain

Actual result:

• HTTP ERROR 400 Problem accessing /series/search/by_catalog. Reason: Required String parameter 'catalogNumber' is not present

Also we should fix the following URLs:

• /account/activate?key={key}
• /series/add?category={category}
• /site/events?page={page}

Regression from #514