Remove JPA annotations from apex-pdp code

Remove JPA annotations from apex-pdp code

This review is part of a series of reviews to move the apex-pdp state
machine model to use the base model types in policy models.

Persistence of policies for apex-pdp is now implemented in PAP and API.
The historic direct load and save functionality for APEX policy state
machine models to and from databases is no longer used and no longer
supported.

This commit removes JPA annotations form apex-pdp code.

Subsequent reviews will mvoe the mdoel across to use the policy models
base model types.

Issue-ID: POLICY-1820
Change-Id: I91a45a0ca6c88f9ba4b201bad920065f95ffb31e
Signed-off-by: liamfallon <liam.fallon@est.tech>