Deprecate `perf_patterns`

[vkarak]

These will be deprecated in favour of the @sanity_function, @performance_function and perf_variables. This is a major disruption. It also requires #2082.

[vkarak]

I'm not convinced that we should deprecate sanity_patterns, because it allows us to define the sanity checking in the class body if we don't need to refer test attributes, such as stdout. Not referring to stdout is not so uncommon, e.g., Gromacs tests look only into md.log and not in stdout.

The story about perf_patterns is different, since they can be fully replaced by the perf_variables attribute.

What we could do though about sanity_patterns is to rename the variable, because this name is purely due to historical reasons. We could rename it to sanity_check and we should also define what the co-existence of sanity_functions and sanity_patterrns mean. Currently, this is disallowed.

[vkarak]

We decided not to deprecate this now as it would be a major disruption for the framework's users. Nonetheless, none of the new examples in the framework use perf_patterns since a while.