Merged PR 348: #2462 - Refactor of DatabaseClient and DatabaseServer

## Summary
Refactor of `DatabaseClient` and `DatabaseService` to update how connection IDs are generated. These are now provided by DatabaseService when establishing a connection.
Creation of `DatabaseClientConnection` class. This is used by `DatabaseClient` to hold a dictionary of active db connections.

## Test process
Tests have been updated to reflect the changes and all pass

## Checklist
- [X] PR is linked to a **work item**
- [X] **acceptance criteria** of linked ticket are met
- [X] performed **self-review** of the code
- [X] written **tests** for any new functionality added with this PR
- [X] updated the **documentation** if this PR changes or adds functionality
- [ ] written/updated **design docs** if this PR implements new functionality
- [X] updated the **change log**
- [X] ran **pre-commit** checks for code style
- [X] attended to any **TO-DOs** left in the code

Related work items: #2462

tests/e2e_integration_tests/test_uc2_data_manipulation_scenario.py

@@ -4,7 +4,7 @@ from primaite.game.game import PrimaiteGame
 from primaite.session.environment import PrimaiteGymEnv
 from primaite.simulator.network.hardware.nodes.host.computer import Computer
 from primaite.simulator.network.hardware.nodes.host.server import Server
-from primaite.simulator.system.applications.database_client import DatabaseClient
+from primaite.simulator.system.applications.database_client import DatabaseClient, DatabaseClientConnection
 from primaite.simulator.system.applications.red_applications.data_manipulation_bot import DataManipulationBot
 from primaite.simulator.system.services.database.database_service import DatabaseService
 from tests import TEST_ASSETS_ROOT
@@ -20,23 +20,23 @@ def test_data_manipulation(uc2_network):
 
     web_server: Server = uc2_network.get_node_by_hostname("web_server")
     db_client: DatabaseClient = web_server.software_manager.software.get("DatabaseClient")
-
+    db_connection: DatabaseClientConnection = db_client.get_new_connection()
     db_service.backup_database()
 
     # First check that the DB client on the web_server can successfully query the users table on the database
-    assert db_client.query("SELECT")
+    assert db_connection.query("SELECT")
 
     # Now we run the DataManipulationBot
     db_manipulation_bot.attack()
 
     # Now check that the DB client on the web_server cannot query the users table on the database
-    assert not db_client.query("SELECT")
+    assert not db_connection.query("SELECT")
 
     # Now restore the database
     db_service.restore_backup()
 
     # Now check that the DB client on the web_server can successfully query the users table on the database
-    assert db_client.query("SELECT")
+    assert db_connection.query("SELECT")
 
 
 def test_application_install_uninstall_on_uc2():