feature: TCG RIM Support

[tarunbang]

Add support for metadata fields as per section 4 of TCG RIM in CoSWID.
• BindingSpecVersion
• PlatformManufacturerId
• PlatformManufacturerStr
• PlatformModel
• FirmwareManufacturer
• FirmwareManufacturerId

Also, please add other related extensions.

[thomas-fossati]

Thanks @tarunbang for pointing out the need for this extension.

For reference, the normative CDDL for this extension can be found at https://github.com/sacmwg/draft-ietf-sacm-coswid/blob/master/concise-swid-rim-extension.cddl

We need to add to four extension points:

• $$coswid-extension
• $$directory-extension
• $$resource-extension
• $$process-extension

Note also that, because the RIM extension is using any-uri, so this feature depends on (or better, is related to) #35