community[minor]: add Cassandra Database Toolkit (#20246)

**Description**: ToolKit and Tools for accessing data in a Cassandra
Database primarily for Agent integration. Initially, this includes the
following tools:
- `cassandra_db_schema` Gathers all schema information for the connected
database or a specific schema. Critical for the agent when determining
actions.
- `cassandra_db_select_table_data` Selects data from a specific keyspace
and table. The agent can pass paramaters for a predicate and limits on
the number of returned records.
- `cassandra_db_query` Expiriemental alternative to
`cassandra_db_select_table_data` which takes a query string completely
formed by the agent instead of parameters. May be removed in future
versions.

Includes unit test and two notebooks to demonstrate usage. 

**Dependencies**: cassio
**Twitter handle**: @PatrickMcFadin

---------

Co-authored-by: Phil Miesle <phil.miesle@datastax.com>
Co-authored-by: Bagatur <22008038+baskaryan@users.noreply.github.com>
Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/community/langchain_community/tools/__init__.py

@@ -70,6 +70,11 @@ if TYPE_CHECKING:
     from langchain_community.tools.brave_search.tool import (
         BraveSearch,  # noqa: F401
     )
+    from langchain_community.tools.cassandra_database.tool import (
+        GetSchemaCassandraDatabaseTool,  # noqa: F401
+        GetTableDataCassandraDatabaseTool,  # noqa: F401
+        QueryCassandraDatabaseTool,  # noqa: F401
+    )
     from langchain_community.tools.cogniswitch.tool import (
         CogniswitchKnowledgeRequest,  # noqa: F401
         CogniswitchKnowledgeSourceFile,  # noqa: F401