Resolve "Export issue time tracking information"

What does this MR do?

Per issue added:

• Current time estimate. Field Time Estimate
• Current time spent. Field Time Spent
• The format of the two fields should be in seconds

Are there points in the code the reviewer needs to double check?

• check that logic is correct
• check if additional documentation/changelog entry needed

Why was this MR needed?

Need to have an ability to see estimates/reports in exported file.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #1406 (closed)