Fix #356

[DomiiBunn]

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Description

Fixes #356

Added a more graceful disconnect when removing an agent to ensure socket.io is not in a "stuck" state where it attempts to keep an open connection to a deleted agent as well as a re-trigger of sendAgentList to ensure the UI has a quick update on agent deletion.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• [x] My code follows the style guidelines of this project
• [x] I ran ESLint and other linters for modified files
• [x] I have performed a self-review of my own code and tested it
• [x] I have commented my code, particularly in hard-to-understand areas (including JSDoc for methods)
• [x] My changes generate no new warnings