symmetric relations: replace bogus rql2sql translation by a hook
The hook ensures X r Y => Y r X iff r is symmetric.
The rql-no-hook data importer receives a small amendment but note
that:
* there exist no test for it
* its actual semantics are undefined
Hence we cannot prove this hunk breaks nothing, because we cannot
prove anything.
Closes #3259713.
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception