fix(ui) Refresh executions on Ingestion page when they are visible

[chriscollins3456]

Fixes a bug that only occurs sometimes when we're unlucky where we don't fetch the executions list because the lastRefresh time did not change. This was happening because new Date().getMilliseconds() will return how many milliseconds into the second we are, not the total number of milliseconds since the epoch. That means that since we refresh exactly every 3 seconds, there's a real chance that occasionally this number is the same as the previous lastRefresh and we don't refresh the executions list. Fix this by setting lastRefresh as the number of milliseconds since the epoch so it's always new.

I also noticed that we were refreshing every executions list from every source that was opened at any point, even if it is now closed. So I added a check to only refresh if the executions list is open.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[github-actions]

Unit Test Results (build & test)

504 tests  ±0   504 ✔️ ±0   9m 14s ⏱️ +57s
117 suites ±0       0 💤 ±0 
117 files   ±0       0 ❌ ±0 

Results for commit 3a1e30a. ± Comparison against base commit ae577dd.

[jjoyce0510]

Nice PR!