Next iteration in IDEA event search form, result page and detail page design.

This commit contains following design changes and fixes:

* Fixed the issue with duplicated HTML identifiers for datetime selects.
* Written macros for rendering search dropdown buttons for source addresses, categories and abuse groups.
* Modified accessors in internal IDEA representation.
* Implemented implicit sorting by storage time in case it was chosen in the search form.
* Additional minor design fixes and tweaks.

(Redmine issue: #3734)