media: visl: Add a tpg_verbose parameter

The text written on the output frames stable for a given input.
Remove the unstable elements like pointers, buffer indexes or queues
status so that frames are always identical and can be compared against
a reference in automatic tests.

As the unstable information can be relevant when debugging the API, add
a tpg_verbose parameter to show them.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>