Merge simtrace-analyser-server into simtrace2_pysniff.server

Add simtrace2-pysniff-server CLI — HTTP API for simtrace-analyser PWA.
Two capture modes: GSMTAP UDP listener (compatible with simtrace2-sniff)
or direct SIMtrace2 hardware capture. SQLite storage with sessions +
messages tables. REST API with CORS.

server/ sub-package: database.py, capture.py, server.py, __main__.py

README updated with server usage section.
pyproject.toml: simtrace2-pysniff-server script entry added.

simtrace2_pysniff/server/__init__.py

@@ -0,0 +1 @@
+"""simtrace2-pysniff server sub-package."""