feat: change default graph to contain deepgram & fish only

[plutoless]

Purpose

The purpose for this commit are:

• to provide a default graph which matches what developer need to achieve their first success.
• to avoid providing a catesian product of graphs for using different providers with same connection logic
• providers should be easy to switch between, especially for stt, tts, llm, llmv2v

Tasks

• Make deepgram + fish the default local run setup
• Update playground ui to change the default graph - it should use a placeholder now because different example folder may not necessarily contain the default graph name hard coded in playground
• Support module switch on web server api
• Support module switch on playground
• Support module switch on demo - not needed
• Clean up property.json after module switch is done
• Only modules exist in the graph should be displayed or switched
• Playground change all write to property.json via dev-server
• When switch module or adding property, a default value should be provided to give developer a more friendly start. This value should read from each extension's default property.json
• Readme update
• Remove Graph Designer from default docker compose setup
• Add default property value for all replacable modules
• Do environment variables check for start request
• Support tool binding in module picker

Screenshots