Add versionning to inventory entities

[gberche-orange]

Expected behavior

• As an osb-cmdb operator

• In order to troubleshoot and diagnose inventory migration issues among osb-cmdb upgrades

• I need inventory entities to have attached meta-data label with a format version:

  • Space
  • Service Instance
  • Service Key

• As an osb-cmdb developer

• In order to introduce inventory migration steps during cmdb upgrades

• I need to have inventory to include a version/schema number

Observed behavior

Inventory entities don't yet have a schema version number.

Affected release

Reproduced on version 0.9