Make `FirstNames` optional in `Persons` records in package metadata #5801

Job	Run time
Cross compiler for s390x	27m 16s
Test in OpenBSD	7m 40s
testinstall - - ubuntu-latest	4m 33s
teststandard - - ubuntu-latest	19m 7s
testmanuals - - ubuntu-latest	5m 56s
testexpect testmockpkg testspecial test-compile testlibgap testkernel testworkspace - - ubuntu-latest	6m 33s
testpackages testinstall-loadall - - ubuntu-latest	26m 0s
makemanuals testmakeinstall - CONFIGFLAGS="--prefix=/tmp/gapprefix" NO_COVERAGE=1 - ubuntu-latest	5m 35s
teststandard - ABI=32 CONFIGFLAGS="" - ubuntu-20.04	18m 10s
testinstall - HPCGAP=yes ABI=64 - ubuntu-latest	7m 53s
testmockpkg testinstall - BOOTSTRAP_MINIMAL=yes - macos-latest	4m 9s
testbugfix - CONFIGFLAGS="--enable-memory-checking" - ubuntu-latest	26m 59s
testbuildsys testmockpkg testinstall - NO_COVERAGE=1 ABI=64 BUILDDIR=out-of-tree CONFIGFLAGS="--enable-valgrind" - ubuntu-latest	4m 32s
testbuildsys testmockpkg testinstall - NO_COVERAGE=1 ABI=32 BUILDDIR=out-of-tree CONFIGFLAGS="" - ubuntu-20.04	4m 55s
testinstall - JULIA=yes CONFIGFLAGS="--enable-debug" - ubuntu-20.04	5m 19s
testmockpkg testinstall - - windows-2019	15m 25s
Send Slack notification on status change	0s
	3h 10m 2s

Provide feedback