HH-44533 move json asserts and fix tests
Merge remote-tracking branch 'origin/HH-44533' into EXP-12974
release 2.21.22 [an.sumin@hh.ru]
add handler tests
append data kwarg in delete requests to query string instead of body
add new MicroHandler test
add simple xsl cache test
remove some dead code
add test for custom 404 and fix error pages
add asciify_url test
service_mock improvements