[Feature Request][Move Analyzer] support spec files

# 🚀 Feature Request

A .move file can only contain some specs for Move Prover. For example, see the following link: https://github.com/move-language/move/blob/main/language/extensions/move-table-extension/sources/Table.spec.move

Currently, `move-analyzer` does not handle these spec files properly.

Start with move-analyzer's current handling of .move files and compare it with the linked language/extensions/move-table-extension/sources/Table.spec.move example. Clarify what support for spec-only files should include, then verify that move-analyzer processes the example correctly; the issue names no tests or additional entry points.

Written by the indexing model from the issue text.