HH-26920 add HTTP 204 support to request response fetching
HH-26920 kill get_url_retry method
HH-31250 small fixes for request/response debug display
HH-31250 fix timebars width
HH-25219 frontik apps testing infrastructure
version up to 2.15.3
Merge branch 'HH-26920' into release_candidate
Merge branch 'HH-31250' into release_candidate
release 2.15.4