Remove the legacy output classes

[pcarruscag]

Proposed Changes

Remove the legacy output and run turbomachinery cases with the single and multizone drivers.
The special turbomachinery outputs have been lost in the process but folks in the Turbo group are working on re-introducing them under the "new" (3 years old already 😄) output classes.

The harmonic balance driver loses very little, it only had one small special output file in the legacy output, we do not have one output per time instance and so the output from all instances is shown on screen and piped to the same history file.
I'm leaving it like this hoping that the vacuum sucks in some new development into HB in SU2.

PR Checklist

• I am submitting my contribution to the develop branch.
• My contribution generates no new compiler warnings (try with --warnlevel=3 when using meson).
• My contribution is commented and consistent with SU2 style (https://su2code.github.io/docs_v7/Style-Guide/).
• I have added a test case that demonstrates my contribution, if necessary.
• I have updated appropriate documentation (Tutorials, Docs Page, config_template.cpp), if necessary.