Add add_class() method to triplestore

[jesper-friis]

Make it easy to add a new class to the triplestore, including annotations, subClassOf, equivalentTo, and disjointWith relations.
It could be defined something like

    def add_class(
            self,
            iri: str,
            subclass_of: "Sequence[str]" = None,
            annotations: dict = None,
            equivalent_to: "Sequence[str]" = None,
            disjoint_with: "Sequence[str]" = None
    ) -> str:
        """Add new class to the triplestore.
    
        Arguments:
            iri: IRI of the new class.  See notes below for how include
                template substitution of a unique reproducible generated
                hash.
            subclass_of: A sequence of strings with superclass IRIs or
                restrictions. Restrictions should use Manchester syntax
                (require [EMMOntoPy]).
            annotations: A dict mapping annotation IRIs to values.
                Use Literal for literal annotation values.
            equivalent_to: A sequence of strings with logical constructs
                that this class is equivalent to using Manchester syntax
                (require [EMMOntoPy]).
            disjoint_with: A sequence of strings with logical constructs
                that this class is disjoint with using Manchester syntax
                (require [EMMOntoPy]).
                    
        Returns:
            The `iri` after template substitution.

        Notes:
            The `iri` argument may contain a template substring of the
            form

                {ID:TYPE.LENGTH}

            which will be substituted with a unique but reproducible
            hash of `ID` and the triplestore `base_iri`, where `ID` is
            a unique user-provided identifier string for this class.
            The ":TYPE" (defaults to "uuid") and ".LENGTH" parts are
            optional.

            `TYPE` specifies how the hash is calculated and encoded
            and should be one of "uuid", "hex" or "base64". The "uuid"
            type correspond to a version 5 UUID (using the URL
            namespace), while the "hex" and "base64" types correspond
            to a hash generated with `urllib.shake_128()` encoded as
            hexidecimal or base64, respectively.
    
            If `LENGTH` is given, it specifies the number of
            substituted characters for the "hex" and "base64" types.

            For example, an IRI for EMMO would be `EMMO["EMMO_{uuid}"]`,
            where `EMMO` is a namespace.

        References:
            [EMMOntoPy]: https://pypi.org/project/EMMOntoPy/
        """

Also, add issues similar methods

add_annotation(self, iri: str, annotations: dict = None, subproperty_of: "Sequence[str]" = None, domains: "Sequence[str]" = None, ranges: "Sequence[str]" = None, equivalent_to: "Sequence[str]" = None) -> str

add_object_property(self, iri: str, annotations: dict = None, subproperty_of: "Sequence[str]" = None, domains: "Sequence[str]" = None, ranges: "Sequence[str]" = None, characteristics: "Sequence[str]" = None, equivalent_to: "Sequence[str]" = None, disjoint_with: "Sequence[str]" = None, inverse_of: "Sequence[str]" = None) -> str 

add_data_property(self, iri: str, annotations: dict = None, subproperty_of: "Sequence[str]" = None, domains: "Sequence[str]" = None, ranges: "Sequence[str]" = None, characteristics: "Sequence[str]" = None, equivalent_to: "Sequence[str]" = None, disjoint_with: "Sequence[str]" = None) -> str 

add_individual(self, iri: str, annotations: dict = None, types: "Sequence[str]" = None, same_as: "Sequence[str]" = None, different_from: "Sequence[str]" = None, object_properties: "Sequence[str]" = None, data_properties: "Sequence[str]" = None, neg_object_properties: "Sequence[str]" = None, neg_data_properties: "Sequence[str]" = None) -> str