Transformations: Add Group to Nested Tables Transformation (#79952)

* Stub group to subframe transformation

* Get proper field grouping

* Mostly working but fields not displaying 😭

* Fix display processing in nested tables

* Modularize and start merging groupBy and groupToSubrame

* Get this working

* Prettier

* Typing things

* More types

* Add option for showing subframe table headers

* Prettier

* Get tests going

* Update tests

* Fix naming and add icons

* Betterer fix

* Prettier

* Fix CSS object syntax

* Prettier

* Stub alert for calcs with grouping, start renaming

* Add logic to show warning message for calculations

* Add calc warning

* Renaming and feature flag

* Rename images

* Prettier

* Fix tests

* Update feature toggle

* Fix error showing extra blank row

* minor code cleanup

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Co-authored-by: nmarrs <nathanielmarrs@gmail.com>

docs/sources/setup-grafana/configure-grafana/feature-toggles/index.md

@@ -87,6 +87,7 @@ Some features are enabled by default. You can disable these feature by setting t
 | `canvasPanelPanZoom`                   | Allow pan and zoom in canvas panel                                                                                                                                                           |
 | `regressionTransformation`             | Enables regression analysis transformation                                                                                                                                                   |
 | `alertingPreviewUpgrade`               | Show Unified Alerting preview and upgrade page in legacy alerting                                                                                                                            |
+| `groupToNestedTableTransformation`     | Enables the group to nested table transformation                                                                                                                                             |
 
 ## Experimental feature toggles