Rename `lastVerified` to `lastUpdated`

[masih]

There are two fields in the status that convey information about the state of a deal: status and lastVerified. The status filed is an enum of strings that shows the status of the deal, e.g. slashed, where the lastVerified filed shoes the latest time at which the status was checked.

The use of the term Verified in the lastVerified filed can cause confusion on what the date means.

To avoid confusion, and make it clear that it only represents the date at which the status was updated rename it to lastVerified