Core: Share ObjectMapper instances

"KOGITO-5807 Public API: Share ObjectMapper instances with Quarkus" has been resolved but we still need to share instances in the core.

even if we may decide to use the OM used in Quarkus/Spring, it should be still kept "logically" separate from the one of the APIs; thus:

1) define a separate interface

2) use the same mechanism of the APIs, but with that new interface

 
we probably can share internal object mapper that already exists in other places, mainly to do data conversion, see

kogito-runtimes/jbpm/jbpm-flow/src/main/java/org/jbpm/process/core/transformation/JsonResolver.java
Line 37 in 3283958
private final ObjectMapper objectMapper;

kogito-runtimes/jbpm/jbpm-flow/src/main/java/org/jbpm/process/instance/impl/util/TypeTransformer.java
Line 36 in fdc2739
private ObjectMapper mapper;

kogito-runtimes/jbpm/jbpm-flow/src/main/java/org/jbpm/util/JsonSchemaUtil.java
Line 43 in 22195a1
private static ObjectMapper mapper = new ObjectMapper();

kogito-runtimes/kogito-codegen-modules/kogito-codegen-processes/src/main/java/org/kie/kogito/codegen/process/persistence/proto/AbstractProtoGenerator.java
Line 36 in f855f1d
protected final ObjectMapper mapper;