`RESET LAYOUT` microflow option is missing from mxcli entirely

[MendixMau]

Solution exists in fork: already implemented in engalar/mxcli (commit 2fabbac31). See below for the reference implementation and its own regression test.

Environment: mxcli (RnD/upstream, commit 504aec6), Mendix 11.12.0 project (EmptyTest base).

Steps to reproduce:

create module ZKT28;
/
create microflow ZKT28."MF_Test" () reset layout
begin
	declare "X" as Boolean;
end

Run mxcli check script.mdl.

Expected behavior: Either the RESET LAYOUT clause is supported (per the community fork's
implementation, it's a useful escape hatch when a script author wants Studio Pro to
re-derive activity positions from scratch instead of accepting mxcli's computed layout), or, if
it's intentionally out of scope, mxcli syntax microflow / the grammar docs should say so
explicitly rather than the original bug report implying it exists but silently misbehaves.

Actual behavior: reset/layout are not recognized tokens at all — mxcli check fails
with mismatched input 'reset' expecting {RETURNS, BEGIN, FOLDER, COMMENT}. There is no
check/exec disagreement to fix here; this is a missing-feature report, not a bug report, once
verified against the actual grammar source.

Already implemented in engalar/mxcli (see mdl/grammar/domains/MDLMicroflow.g4:112, commit
2fabbac31 for the original feature). Their own regression test
(TestResetLayoutProducesValidCoordinates in mdl/executor/flowbuilder_graph_v2_test.go)
documents and guards against a coordinate-corruption bug they hit and fixed along the way —
worth reading before porting, so the same mistake (clearing RelativeMiddlePoint to ""
instead of recomputing it) isn't repeated upstream.