## [Observability RAC] Alerts table post-`EuiDataGrid` style updates
This PR updates styles in the Observability `Alerts` table, as a follow-up to the [TGrid migrating to use `EuiDataGrid` for rendering](https://github.com/elastic/kibana/pull/106199), and [this PR](https://github.com/elastic/kibana/pull/105446), which improved the alerts table columns.
- The `Reason` column uses up the remaining width, a follow-up task from https://github.com/elastic/kibana/pull/105446
- This task was originally tracked by https://github.com/elastic/kibana/issues/105227
- Increased the font weight and vertically aligned the `Actions` header with the other columns
- ~Removed the `Status` column~ (EDIT: we won't remove this, per a discussion w/ UX)
- Increased the width of the `Triggered` column
- ~Renamed the `Duration` column to `Alert duration`~ (EDIT: we won't rename this, per a discussion w/ UX)
- Eliminated the gap between actions
- Added truncation to the `Reason` column
### Before
### After
<img width="1280" alt="after" src="https://user-images.githubusercontent.com/4459398/126716690-be310fdf-3760-4014-998b-3c89099c2564.png">
### Desk testing
- To desk test the `Observability > Alerts` page, add the following settings to `config/kibana.dev.yml`:
```
xpack.observability.unsafe.cases.enabled: true
xpack.observability.unsafe.alertingExperience.enabled: true
xpack.ruleRegistry.write.enabled: true
```
cc @mdefazio
4d92dafa9e
