feat: introduce source maps for templates (#15011)

The main use case for the generated source maps is to give
errors a meaningful context in terms of the original source
that the user wrote.

Related changes that are included in this commit:

* renamed virtual folders used for jit:
  * ng://<module type>/module.ngfactory.js
  * ng://<module type>/<comp type>.ngfactory.js
  * ng://<module type>/<comp type>.html (for inline templates)
* error logging:
  * all errors that happen in templates are logged
    from the place of the nearest element.
  * instead of logging error messages and stacks separately,
    we log the actual error. This is needed so that browsers apply
    source maps to the stack correctly.
  * error type and error is logged as one log entry.

Note that long-stack-trace zone has a bug that 
disables source maps for stack traces,
see https://github.com/angular/zone.js/issues/661.

BREAKING CHANGE:

- DebugNode.source no more returns the source location of a node.  

Closes 14013

packages/compiler/src/output/output_interpreter.ts

@@ -304,7 +304,10 @@ class StatementInterpreter implements o.StatementVisitor, o.ExpressionVisitor {
         (entry) => (result as any)[entry.key] = entry.value.visitExpression(this, ctx));
     return result;
   }
-
+  visitCommaExpr(ast: o.CommaExpr, context: any): any {
+    const values = this.visitAllExpressions(ast.parts, context);
+    return values[values.length - 1];
+  }
   visitAllExpressions(expressions: o.Expression[], ctx: _ExecutionContext): any {
     return expressions.map((expr) => expr.visitExpression(this, ctx));
   }