Multiple Crashes And Fixes

[aggarwalpulkit596]

Describe the bug
1.Incorrect Nested query #1345
2.Use of ObjectMapper instead of jacksonObjectMapper() in #1592
3.Crash in favorite event view holder because of null object reference in item_favourite

[aggarwalpulkit596]

@iamareebjamal I'm extremely sorry for this should've tested after merging and rebasing the PR's it wouldn't happen again
Making a PR right away