[tuner] Remove legacy tuner path (#756)

This PR removes the old code paths for the tuner following the large
refactoring done in #606 and
#704.
- The old compilation and benchmarking logic for models and dispatches
are now gone, and the unified `benchmark` and `compile` functions should
be used instead.
- Much of the dispatch parsing logic is removed, and dispatch parsing is
now done by 2 DispatchParser implementations for contraction ops and
convolution ops.
- The example tuning clients in `tuner/examples` for dispatches and
punet are removed, since they use the old path. The new example to
follow is in `tuner/examples/test`.
- The candidate generation `tune` function is removed, and the
`generate_configs_and_td_specs` should be used to generate candidates
instead.
- Many utility functions, structs, and struct fields are now removed,
since they are no longer used.
- All tests testing the old path are removed.

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Signed-off-by: Max Dawkins <[email protected]>

Author: Max191