Improved image preview loading for **Tasks**, **Jobs** and **Projects**
views
Backend behaviour change: creating image previews by request and storing
them in the cache
Added corresponding endpoints:
tasks/{id}/preview
projects/{id}/preview
jobs/{id}/preview

Demonstration(added random 0-1s delay for demo purposes):
https://user-images.githubusercontent.com/41117609/208106321-951b8647-6e6b-452e-910c-31c4d0b8682d.mp4
https://user-images.githubusercontent.com/41117609/208106339-2d3a5a7b-d422-4b27-9e76-08729022e1ca.mp4