Refactor MetaDB Schema

[miyurud]

Currently, there are fields such as vertexcount, edgecount, centralpartitioncount which need to be changed to vertex_count, edge_count, central_partition_count. This change has to be carefully propagated to all the code segments and verified with integration tests.

[nocturnalnerds]

Hi, I’m new to open source and this looks like a manageable task to get started. I’d be happy to work on refactoring these fields and ensuring the changes are properly propagated.