added multi column support for postgres

[xialingxiao]

to install it to a django model (using the example used in the test case of this commit)

@architect.install(
    "partition",
    type="range",
    subtypes=["integer", "date"],
    constraints=["1", "month"],
    columns=["source_file_id", "date"],
)

[ghost]

@maxtepkeev is this not merged because of the failed checks or code/architecture issues? If I get the checks to pass, would this be merged?

I'm very interested in adding the support for multi column.