refactor(ivy): simplify differentiation of LView, RNode, LView, LContainer, StylingContext (#28947)

For efficiency reasons we often put several different data types (`RNode`, `LView`, `LContainer`,
`StylingContext`) in same location in `LView`. This is because we don't want to pre-allocate
space
for it because the storage is sparse. This file contains utilities for dealing with such data
types.
How do we know what is stored at a given location in `LView`.
- `Array.isArray(value) === false` => `RNode` (The normal storage value)
- `Array.isArray(value) === true` => than the `value[0]` represents the wrapped value.
  - `typeof value[TYPE] === 'object'` => `LView`
     - This happens when we have a component at a given location
  - `typeof value[TYPE] === 'number'` => `StylingContext`
     - This happens when we have style/class binding at a given location.
  - `typeof value[TYPE] === true` => `LContainer`
     - This happens when we have `LContainer` binding at a given location.
NOTE: it is assumed that `Array.isArray` and `typeof` operations are very efficient.

PR Close #28947

packages/core/src/render3/interfaces/styling.ts

@@ -7,7 +7,10 @@
  */
 import {StyleSanitizeFn} from '../../sanitization/style_sanitizer';
 import {RElement} from '../interfaces/renderer';
+import {LContainer} from './container';
 import {PlayerContext} from './player';
+import {LView} from './view';
+
 
 /**
  * The styling context acts as a styling manifest (shaped as an array) for determining which
@@ -263,7 +266,7 @@ export interface StylingContext extends
   /**
    * Location of element that is used as a target for this context.
    */
-  [StylingIndex.ElementPosition]: RElement|null;
+  [StylingIndex.ElementPosition]: LContainer|LView|RElement|null;
 
   /**
    * A numeric value representing the configuration status (whether the context is dirty or not)