A node in a generic boolean CONTAINS filter tree, shared by GraphQL backends
(Wix, Magento2) whose filter input uses the same and/or/not/term
shape. Either a leaf ContainsTermFilter or a boolean combinator.
Translates a SearchAst into a generic boolean CONTAINS filter tree of
the form { and|or|not | term: { field, op: "CONTAINS", values } }. Used by
GraphQL suppliers that accept this structure server-side, so the boolean
matching happens on the backend in a single request.
A leaf field-match condition in a CONTAINS filter tree.