More manual page fixes

non-test and tutorial makefiles only need rules.doc not the full rules

Commit-type: documentation

Only makefiles in the test and tutorial directories need lib/petsc/conf/test

Commit-type: housekeeping

Fix manual pages based on reports from Jacob's lint tool

Commit-type: documentation

Remove now unneeded SOURCE* variables from makefiles

Commit-type: configure, housekeeping

Remove unneeded SOURCEH from makefiles

No longer used by docs or build

Clean up PETSc str ops to use more secure implementations where possible. These include:

- Use PetscStrncpy()/PetscStrlcat()/PetscMemcpy() over PetscStrcpy()/PetscStrcat()
- Use PetscArraycpy() over

Clean up PETSc str ops to use more secure implementations where possible. These include:

- Use PetscStrncpy()/PetscStrlcat()/PetscMemcpy() over PetscStrcpy()/PetscStrcat()
- Use PetscArraycpy() over PetscMemcpy() as appropriate for string buffer copying
- Use built in string from name over hardcoding
- Use sizeof over hardcoded length
- Replace some Strlcat with Strncpy when offset is known

show more ...

Fix C++20 implicit enum-float conversions

Remove empty preprocessor variables