Prostoria 534 adjust matrix field schema

[JakovKnezovicc]

• set ngremotemedia field metadata property additional properties to true
• make matrix field shchema generic using additional properties

[emodric]

This also needs to require ^1.0.2 of netgen/openapi in composer.json, since that's the version that allowed true for additionalProperties.

[JakovKnezovicc]

This also needs to require ^1.0.2 of netgen/openapi in composer.json, since that's the version that allowed true for additionalProperties.

My bad i forgot. Added in e8e0d5c

[emodric]

Thanks @JakovKnezovicc !