The similarity function syntax is:
`similarity_<metric_name>(<vector>, <vector>)`
Where `<metric_name>` is one of `cosine`, `euclidean` and `dot_product`
matching the intended similarity metric to be used within calculations.
Where `<vector>` is either a vector column name or vector literal.
Add `vectorSimilarityArgs` symbol that is an extension of `selectionFunctionArgs`,
but allowing to use the `value` as an argument as well as the `unaliasedSelector`.
This is needed as the similarity function syntax allows both the arguments to be
a vector value, so the grammar needs to recognize the vector literal there as well.
Since we actually support `SELECT`s with constants since this patch,
return true instead of throwing an error while trying to convert the function call
to constant.
b03d520aff