Support for OSN custom ratings

[harshith-d]

• Add Saudi Arabia parental guidance rating bodies to ebu_ParentalGuidanceCodeCS:
  • SA-OSN (_78) — OSN custom ratings for Saudi Arabia

Rating values

Rating code	Pref label	Alt label	Description
_78.1.1	FAM	—	Suitable for all the family.
_78.1.2	PG	—	Parental guidance advised
_78.1.3	PG15	PG 15, PG 15-D, PG15-D, 15	Suitable for ages 15 and older.
_78.1.4	18	—	Unsuitable for ages under 18.
_78.1.5	R	—	Adults only.