Adding read/write support to Baikal and BaikalVacuum

[Samuel Cupp]

This update to Baikal and BaikalVacuum adds READ and WRITE declarations to the schedule.ccl files. It also adds a new function specify_Driver_BoundaryConditions_Baikal* that calls the function Driver_SelectVarForBC to select boundary conditions for all variables and register them with PreSync for automated scheduling. Another small change was the addition of checkpoint="no" to some auxiliary and RHS variables which don’t need checkpointing. Copies of the Baikal* tests are also included with PreSync enabled, so that the thorns can be validated both with and without PreSync.

The PR for the thorn is https://bitbucket.org/zach_etienne/wvuthorns/pull-requests/13

and the PR for NRPy+ to autogenerate the thorn is https://github.com/zachetienne/nrpytutorial/pull/56.

[Leonardo Werneck]

@Leonardo Werneck will be the reviewer.

[Samuel Cupp]

This enhancement is now included as part of the Toolkit in the ET_2023_05 release.