Add real terminal support

[James4Ever0]

As the demo from Devin has shown, its agent is capable of interacting with real terminal while other open source ones such as OpenDevin unable to.

Hereby I made some necessary progress over this very agent by developing a complete terminal agent environment. Here are some of its features.

You can see the position of the cursor, the range of the selected text.

You can also capture a screenshot of the terminal with cursor denoted in red.

Grayscale augmented terminal gives high contrast to the red cursor, making the agent easier to locate it.

Devon can certainly integrate this into its core, making it more competitive.

You can learn more about it here.