check/describe/LSP follow-ups: CE0109 on a void call's output, flow-wide duplicate warning, LSP void calls, MPR010 on native pages

[ako]

Follow-ups from #953 / PRs #957 and #958.

1. check misses CE0109 on a void call's output name. Using the output name of a call to a void Java/JavaScript action is CE0109 "Undefined variable" in mxbuild (measured on 11.13 in fix(check): void action calls declare no variable; unknown call parameters not hidden (#953 items 1, 7) #958). check does not flag it.
2. describe's duplicate-output warning treats if/else branches as separate scopes. mxbuild names are flow-wide (CE0111 across branches, measured in fix(check): void action calls declare no variable; unknown call parameters not hidden (#953 items 1, 7) #958). An existing test pins the old branch scoping; update it to match mxbuild.
3. The LSP still flags void calls to actions stored in the project. It validates without a project, so it cannot tell that the action is void. When the workspace has a project, resolve the action. Otherwise treat an unresolvable call as possibly void, as check does.
4. MPR010 ("wrap in a layoutgrid") probably fires on native pages, which have no layout grid. This is the same web-only assumption MPR012 had. Measure first, then skip native pages if the rule doesn't apply. LintContext.NativePages() came in with fix(lint/check): #953 items 2-6 — BUTTON01 nested grids, native pages, return-only flows, CONV006 grouping, report --modules #957.