Define common base package for MerkleDB/JasperDB module

Currently the `swirlds-jasperbd` module has that module name/basepackage `com.swirlds.jasperdb` define in the `module-info.java`. Based on https://github.com/hashgraph/hedera-services/issues/6611 all packages and sources should be under that base package. Currently the module contains sources under `com.swirlds.jasperdb` and `com.swirlds.merkledb`. We should refactor that behavior.

Initial questions: Should the name be `merkledb` or `jasperdb`?

Start with the swirlds-jasperbd module and its module-info.java, then inventory sources under com.swirlds.jasperdb and com.swirlds.merkledb. Resolve whether merkledb or jasperdb is the common base package, align the module's packages and sources with that decision, and verify that the module remains consistent.

Written by the indexing model from the issue text.