Add @angular-stdlib/ssn

[magnasilvar]

Relevant Package

This feature request is for the new @angular-stdlib/ssn.

Is your feature request related to a problem? Please describe.

No.

Describe the solution you'd like

Manage / check validity of Social Security Number.
Add custom form validator for french SSN (NIR) :

• Add frSsn|nir template-driven form validator

• Add frSsn|nir reactive form validator

• Add public service to generate NIR key.

Resource link :

• http://xml.insee.fr/schema/nir.html