…#106199)

## [RAC] [TGrid] Migrate the TGrid's rendering to `EuiDataGrid`

This PR migrates TGrid's rendering to use `EuiDataGrid`, per the screenshots below:

![o11y_alerts](https://user-images.githubusercontent.com/4459398/126413504-e825a5a2-1cb5-475e-b514-01fb819793e1.png)

![security_solution_alerts](https://user-images.githubusercontent.com/4459398/126413546-28df8f28-fa81-4b97-91c6-667589ea683c.png)

Related RAC Issue: elastic/security-team#1299

### Prerequisites to deleting legacy code (reducing bundle sizes)

To reduce the size of the `timelines` and `security_solution` plugins, legacy TGrid code and the dependency on `react-beautiful-dnd` will be removed in a follow-up PR.

- Related issue: elastic#105941

The legacy code and dependencies will be deleted when the following tasks are completed (in follow-up PRs):

- Sorting: Map `redux` sort state to `EuiDataGrid`'s `sorting` prop
- Actions: Migrate draggable hover actions to `EuiDataGrid` `cellActions`
  - related PR: <elastic#105500>
- Use `BrowserFields` to display field metadata when hovering over a column
  - related PR: <elastic#105207>
- Migrate Security Solution's actions column config from a single column to multiple columns

### Desk testing

To desk test this PR, you must enable feature flags in the Observability and Security Solution:

- 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
```

- To desk test the TGrid in the following Security Solution, edit `x-pack/plugins/security_solution/common/experimental_features.ts` and in the `allowedExperimentalValues` section set:

```typescript
tGridEnabled: true,
```