Command filter: two presets, and a "Selected: N" summary (v2.7.2)

- the 'Proactive + events' preset is gone: the proactive one (FETCH,
  TERMINAL PROFILE and the SW 91xx initiators) plus the individual ENVELOPE
  entry cover it, and its Russian key is removed with it
- with several entries checked the filter button now reads "Selected: N"
  («Выбрано: N») instead of "N commands"; a single entry keeps showing its
  name and an empty selection stays "All commands"
- tests: the removed preset's case is replaced by an absence pin in the menu
  test, and the summary case follows the new wording; 527 Python + 72 Node
  tests
- README/README_RUS list two presets; PWA_VERSION/pyproject/version.py 2.7.2,
  SW cache simtrace-analyser-v82

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'simtrace-analyser-v81';
+const CACHE = 'simtrace-analyser-v82';
 
 const PRECACHE = [
     'index.html',