feat: SPDX license instead of expression

[jkowalleck]

BASED ON Discussed in #377

have a feature switch, that causes the output to change in behaviour:

instead of

<?xml version="1.0" encoding="UTF-8"?>
<bom xmlns="http://cyclonedx.org/schema/bom/1.4"
     serialNumber="urn:uuid:3e671687-395b-41f5-a30f-a58921a69b79"
     version="1">
    <components>
        <component type="library">
            <group>org.acme</group>
            <name>card-verifier</name>
            <version>1.0.2</version>
            <licenses>
                <expression>(Apache-2.0 OR MIT)</expression>
            </licenses>
        </component>
    </components>
</bom>

the output should look like this:

<?xml version="1.0" encoding="UTF-8"?>
<bom xmlns="http://cyclonedx.org/schema/bom/1.4"
     serialNumber="urn:uuid:3e671687-395b-41f5-a30f-a58921a69b79"
     version="1">
    <components>
        <component type="library">
            <group>org.acme</group>
            <name>card-verifier</name>
            <version>1.0.2</version>
            <licenses>
                <license>
                    <id>Apache-2.0</id>
                </license>
                <license>
                    <id>MIT</id>
                </license>
            </licenses>
        </component>
    </components>
</bom>

[madpah]

Duplicates #354

[jkowalleck]

discussed the topic with @madpah , and we think we will prefer ad different solution:
we will take the opportunity and create a factory in the cyclonedx-python-lib via CycloneDX/cyclonedx-python-lib#304
that accepts any string and will create the fitting license model from it - an expression, a named, or an SPDX one.

[jkowalleck]

might be closed via #417

[jkowalleck]

fixed by #605

[jkowalleck]

This feature will be part of the next/upcoming major release.
Changelog: see #605
Install via: pip install cyclonedx-bom==4.0.0rc1