Propagate tags to the introspection endpoint task list

### Summary

Container instance tags and task tags are missing from the task list returned by the introspection endpoint.

### Description

While metadata endpoints version 2 and 3 introduced new paths that propagate this information, the introspection endpoint doesn't have it yet. For consistency and also because the introspection endpoint is the most direct way to retrieve a list of tasks running on the container instance, it would be very interesting to propagate that information here as well, under the exact same form (i.e. by adding both `ContainerInstanceTags` and `TaskTags` fields in the response), possibly with a new `/v1/tasksWithTags` route.

WDYT? I'd be happy to contribute to make that change possible!