refactor(ivy): move hostVars/hostAttrs from instruction to DirectiveDef (#34683)

This change moves information from instructions to declarative position:
- `ɵɵallocHostVars(vars)` => `DirectiveDef.hostVars`
- `ɵɵelementHostAttrs(attrs)` => `DirectiveDef.hostAttrs`

When merging directives it is necessary to know about `hostVars` and `hostAttrs`. Before this change the information was stored in the `hostBindings` function. This was problematic, because in order to get to the information the `hostBindings` would have to be executed. In order for `hostBindings` to be executed the directives would have to be instantiated. This means that the directive instantiation would happen before we had knowledge about the `hostAttrs` and as a result the directive could observe in the constructor that not all of the `hostAttrs` have been applied. This further complicates the runtime as we have to apply `hostAttrs` in parts over many invocations.

`ɵɵallocHostVars` was unnecessarily complicated because it would have to update the `LView` (and Blueprint) while existing directives are already executing. By moving it out of `hostBindings` function we can access it statically and we can create correct `LView` (and Blueprint) in a single pass.

This change only changes how the instructions are generated, but does not change the runtime much. (We cheat by emulating the old behavior by calling `ɵɵallocHostVars` and `ɵɵelementHostAttrs`) Subsequent change will refactor the runtime to take advantage of the static information.

PR Close #34683

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

@@ -201,6 +201,15 @@ export const enum TNodeProviderIndexes {
  * items are not regular attributes and the processing should be adapted accordingly.
  */
 export const enum AttributeMarker {
+  /**
+   * An implicit marker which indicates that the value in the array are of `attributeKey`,
+   * `attributeValue` format.
+   *
+   * NOTE: This is implicit as it is the type when no marker is present in array. We indicate that
+   * it should not be present at runtime by the negative number.
+   */
+  ImplicitAttributes = -1,
+
   /**
    * Marker indicates that the following 3 values in the attributes array are:
    * namespaceUri, attributeName, attributeValue