The `template` and `isInline` fields were previously stored in a nested
object, which was initially done to accommodate for additional template
information to support accurate source maps for external templates. In
the meantime the source mapping has been accomplished in a different
way, and I feel this flattened structure is simpler and smaller so is
preferable over the nested object. This change also makes the `isInline`
property optional with a default value of `false`.
PR Close#40383
b48eabddb8