modernize the f77 eigenvalue module, prettify #960

Job	Run time
Github \| Docker	51m 17s
Georgia Tech \| Phoenix (NVHPC) (cpu)	1h 45m 45s
Github (ubuntu, mpi, debug, true)	31m 43s
Georgia Tech \| Phoenix (NVHPC) (gpu)	2h 1m 37s
Github (ubuntu, mpi, debug, false)	1h 22m 41s
Github (ubuntu, mpi, no-debug, true)	54m 51s
Github (ubuntu, mpi, no-debug, false)	53m 54s
Github (ubuntu, no-mpi, debug, true)	11m 16s
Github (ubuntu, no-mpi, debug, false)	23m 38s
Github (ubuntu, no-mpi, no-debug, true)	31m 53s
Github (ubuntu, no-mpi, no-debug, false)	18m 23s
Github (macos, mpi, debug, false)	1h 3m 22s
Github (macos, mpi, no-debug, false)	47m 25s
Github (macos, no-mpi, debug, false)	23m 40s
Github (macos, no-mpi, no-debug, false)	21m 58s
	12h 23m 23s

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