Explore using custom struct tags for CycloneDX property versioning

[mrutkows]

If we want to have special processing for JSON encoding/decoding (e.g., marshal/unmarshal) it would be helpful to enable this via custom struct tags.

For example:

// v1.3 added "compositions"
Compositions []CDXCompositions `json:"compositions,omitempty" cdx:"v1.3"`
// v1.4 added "vulnerabilities", "signature"
Vulnerabilities []CDXVulnerability `json:"vulnerabilities,omitempty" cdx:"v1.4"`

[mrutkows]

See https://stackoverflow.com/questions/75023943/golang-unmarshal-with-different-sets-of-struct-tags for some other person's use case

[mrutkows]

Note: this COULD be used as a crude means to add SVCS (data) tags (although they are longish URIs)