Adjust packages to avoid unnecessary uses of `IsContainedInSpan`

[fingolfin]

A bunch of packages could potentially benefit from similar changes. Her are all that use IsContainedInSpan:

• corelg
• ctbllib
• fining
• liealgdb
• polycyclic -- see Use return value of CloseMutableBasis to replace not IsContainedInSpan gap-packages/polycyclic#115, resolved in version 2.18
• qpa
• recog
• repsn
• sla

Found via

rg --type=gap -l IsContainedInSpan pkg/   | sort | cut -d/ -f2 | uniq

Originally posted by @fingolfin in #6287 (comment)