Basic LSP lifecycle

[onbjerg]

Describe the feature

The foundation for a working LSP is the following, which we should implement:

• Responding to lifecycle events (initialize, initialized, shutdown, exit)
• Capability negotiation between server and client
• An LSP config and basic config discovery (e.g. solar.toml and probably also parsing foundry.toml)
• Basic text document management, i.e. textDocument/didOpen, textDocument/didChange, textDocument/didClose.
• Parsing and lowering files when documents change, including in-memory only changes for documents that are managed by the LSP client, and publishing compiler diagnostics to the client.
• Exposing the LSP over CLI (solar lsp).

Additional context

No response