Add rename functionality

[lukaszsamson]

LSP Spec:
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_rename

POC: #676

There are many things that can be renamed:

• function/marco/guard/delegate
• callback/macrocallback
• overridable function/macro
• module
• behaviour
• protocol
• attribute
• variable
• type
• type parameter
• struct field
• record field

Obviously not everything from that list is high proritity