## Summary
We should replace the 'Created' timestamp column with an 'Updated' timestamp column in the table shown on Special:SuggestedInvestigations
## Background
- Cases can now be updated when they have an additional signal match them
-- This means that often a old case can be updated with additional context
--- In these cases it may make the case more relevant to deal with and so should be shown further up the list
- Having a timestamp for when the case was last updated would give allow users to sort by cases based on when they were last interacted with
-- However, the table pager already has too many columns and needs to be shortened to support that
- Sorting by the 'Created' timestamp is useful to see cases in terms of age, but beyond that does not seem to provide further value
-- A 'Updated' timestamp would provide the same information when a case has not been updated
-- Therefore, replacing it with a 'Created' with 'Updated' would likely be an improvement and would avoid adding more columns that causes the space problem to become worse
##User story
As a checkuser I want to filter cases for when they last matched against signals instead of when they were created
## Technical notes
Will require a schema change to add a column that stores the last updated timestamp for the case.
## Acceptance criteria
- [ ] The table pager view has an 'Updated' column showing the last timestamp where the case had a signal match instead of 'Created'