[Human App][Backend] Invalid sorting when reward_amount of the job is sorting criteria

[dnechay]

Describe the bug
There is a paginateAndSortResults common tooling that's being used for sorting of some data returned to Human App UI.

reward_amount of the job is string, not a number, so when you attempt to sort by this field - you get invalid results because paginateAndSortResults uses straightforward way of sorting by comparing values.

To Reproduce
Steps to reproduce the behavior:

1. Go to any page with jobs
2. Click on Reward amount table header and choose "from highest"
3. You will see results returned in an invalid order

Expected behavior
Job sorted by reward amount as numeric value

Screenshots