refactor(lsp): move references to internal types

[benfdking]

• in the hope of moving some of this code to internal without any
  dependencies on lsp code

[Copilot]

Pull Request Overview

This PR refactors the LSP module to use internal types instead of external LSP protocol types for Position and Range. This prepares the code for moving some functionality to internal modules without dependencies on LSP-specific libraries.

• Replaces lsprotocol.types.Position and lsprotocol.types.Range with sqlmesh.core.linter.rule.Position and sqlmesh.core.linter.rule.Range
• Adds conversion functions between LSP and internal types at LSP boundaries
• Updates test files to use internal types

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/lsp/test_reference_model_column_prefix.py	Updates import to use internal Position type
tests/lsp/test_reference_external_model.py	Updates imports and removes LSP-specific helper usage
tests/lsp/test_reference.py	Updates import to use internal Position type
sqlmesh/lsp/rename.py	Adds conversion between LSP and internal types at function boundaries
sqlmesh/lsp/reference.py	Removes LSP type imports and conversion calls, uses internal types throughout
sqlmesh/lsp/main.py	Adds conversion between LSP and internal types at LSP protocol boundaries
sqlmesh/core/linter/rule.py	Adds comparison methods to internal Position class
sqlmesh/core/linter/helpers.py	Minor import reordering