Provide LLM With Language Server Types

[mathewpareles]

When we send messages to an LLM, we want to provide context about relevant types the user can access (including variable and function types). For example, if the user imports the React package, we should give the LLM context about the various attributes in the React object, like React.useContext, React.useState, etc.

To resolve this issue:

1. Access vscode's internal language server and find all of the types in the current file.
2. Modify the sendLLMMessage function so that we always send the relevant variable and function types to the LLM.
3. Bonus: Create a function typeFromName that can access the type of a variable from its name. In the case of duplicates, return all relevant types.