Move dependencies to extras

What

Remove hard dependency on openassetio and openassetio-mediacreation and move to extras

Why

openassetio should always be provided by the host runtime (to ensure we don't have multiple copies loaded simultaneously). Having it as a hard dependency anywhere up the stack causes problems, as pip will try and provision it too, which usually results in a separate static build being installed in addition to whatever the host provides (unless the host is pure python).

ACs

• openassetio moved to a extras dep under the all and deps names
• openassetio-mediacreation moved to an extras dep under the deps name. [TBC]

Inizia individuando la configurazione delle dipendenze del pacchetto e verifica come sono dichiarati i requisiti esistenti per openassetio e openassetio-mediacreation. Verifica che openassetio sia disponibile tramite gli extra all e deps e che openassetio-mediacreation sia disponibile tramite deps; risolvi l’incertezza indicata prima di considerare concluso il lavoro.