Create a filter specification
Expected filter syntax: name:like(value)
When operator is not provided; defaults to like
operator => gt, ge, lt, se, eq, !eq, like, !like, in, !in, between, !between
attribute => must be field name that can be translated to JPA layer; can think of obfuscation; will defer to later times
value => a value to look up (can be comma separated list)
in case of between and not between operator values must be enclosed (x, y)