feat(poc): test suite support

[fredrikaverpil]

Early days. I'm just playing around. But hopefully this will lead to enabling e.g. testify suites.

Aims to fix #25.

To do

• [x] Detect receiver method name using AST/tree-sitter.
• [ ] Detect suite name using AST/tree-sitter.
• [ ] Create lookup between AST-detected suite name vs receiver method name.
• [ ] Augument neotest position tree with lookup resolve for each position, prior to building runspec.
• [ ] Runspec for namespace.