VSA: VSA table - rename the Time column to 'Duration time'

Problem

In the VSA table, the data format of the Time column is unclear.

Solution

1. Rename the Time column to Duration time.
2. Both on project VSA and group VSA.
3. Ensure that documentation / screenshots are updated as part of the issue.

Implementation Guide

• The stage table is a shared component between group and project level VSA, so changing the title in here should apply to both.
• We might also need to update some tests, possibly the stage table tests.