fix: drop the "Reserved for 3GPP" event-name cross-reference (v3.6.22)

The event list tables carried labels like
"12  Reserved for 3GPP - Network rejection (TS 31.111 7.5.2)".  The phrase is
an ETSI-to-3GPP document pointer, not a usage restriction, and it is not
what a user needs - the event name is.

- EVENT_NAMES (PWA + server mirror): the 3GPP-assigned codings carry their
  plain TS 31.111 7.5 name ((I-)WLAN access status, Network rejection, CSG
  cell selection, IMS registration, Incoming IMS data, Data connection
  status change, CAG cell selection, Slices status change).
- 0x20-0x22: "Reserved (future usage)" (no attribution).
- 0x0B/0x14: the spec's full "(single access technology)" / "(multiple
  access technologies)" wording instead of the cryptic "(single)/(multiple)".
- tests pin the exact names and that no name contains the cross-reference.

652 frontend / 500 Python green; version 3.6.22; sw simple-v295.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pysim-simple-server"
-version = "3.6.21"
+version = "3.6.22"
 description = "HTTP REST server wrapping pysim for the SIMple PWA"
 requires-python = ">=3.8"
 # pysim is a git-only dependency installed explicitly by setup.bat/setup.sh.