add PostgreSQLIndexer

[cristianmtr]

As part of https://github.com/jina-ai/internal-tasks/issues/40

As part of jina-ai/jina#2154

SUBTASK

• Docker image running with a Dummy Executor -- get PostgreSQL Docker image and install Jina in it
• Executor performs CRUD ops
• Executor performs DumpRequest

Should inherit from

from jina.executors.indexers import BaseIndexer


class BaseDBMSIndexer(BaseIndexer):
    def add(self, ids, vecs, metas, *args, **kwargs):
        raise NotImplementedError

    def update(self, ids, vecs, metas, *args, **kwargs):
        raise NotImplementedError

    def delete(self, ids, *args, **kwargs):
        raise NotImplementedError

    def dump(self, uri, shards, formats):
        raise NotImplementedError

[carlosb1]

It could be useful to do something similar for other SQL services like Spark? It seems, has more sense for something like hbase

[cristianmtr]

Done in #6897