add labcommon repository submodule

[jcolomb]

As teams cannot be implemented on the main GIN, I would like to shortcut the first release but still have one submodules:

• add the labcommons repository of the organisation in the 07_misc as a submodule
• if the labcommons repository does not exist, do nothing.

NB: on the admin side, it means creating this labcommons repo manually for each organisation.

[jcolomb]

the first part is done, checking for lab commons is too complex at this point