Conversion of Vega to new platform. The vega base path is src/legacy/core_plugins/vega.

The following tasks need to be done:

• Move Vega to new platform [[New Platform Migration Phase I]: convert vega plugin to vis_type_vega #39915] [[Vega] Shim new platform #40032]
• Move UI to React (EUIfication)
  • Vega visualization editor panel ([Vis: Default editor] EUIficate Vega options tab #47473)
• Remove Angular from Vega (the vega vis is one of the remaining Angular visualizations making slight--not too heavy--use of Angular in it's implementation)