Merge the track layout editor into cpp20-modules, ported to modules

The editor branch was written against headers and the PCH, both of which this
branch has done away with, so its own files were ported rather than merged: the
five headers it added are now interface units and their .cpp files module
implementation units.

- editor/{puwg1992,polandmap,turnouts,orthophoto} become eu07.editor.* modules,
  application/planpanel becomes eu07.application.planpanel. The plan tool keeps
  to its own module rather than joining the eu07.simcore partitions: it stands on
  the editor's libraries and eu07.application.uilayer, not on the simulation core,
  so :editoruilayer can export import it without a cycle.
- glm arrives by import eu07.glm, never by include, as the rest of the tree does.
  maj0sted is header-only and glm-free, so its headers stay includes in the global
  module fragment - every unit that names those types includes them itself, since
  a global fragment is not visible across units.
- the one textual conflict was :editoruilayer's include block against this
  branch's imports; resolved this branch's way plus the planpanel import.

Builds with clang 22 (-DWITH_BETTER_RENDERER=OFF) and starts into the editor on
empty ground with -editor alone.

editor/polandmap.cpp

@@ -0,0 +1,45 @@
+module;
+#include <algorithm>
+
+module eu07.editor.polandmap;
+import eu07.glm;
+import eu07.editor.puwg1992;
+
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+namespace editor
+{
+
+namespace
+{
+
+// the country's corners in degrees, wide enough to hold all of it: the Odra in the west, the Bug in
+// the east, the Tatras in the south and the coast in the north
+double const kSouthLatitude = 49.00;
+double const kNorthLatitude = 54.90;
+double const kWestLongitude = 14.10;
+double const kEastLongitude = 24.20;
+
+} // namespace
+
+void poland_extent(glm::dvec2 &Min, glm::dvec2 &Max)
+{
+	// the projection is not axis-aligned with the graticule, so the extremes come from projecting
+	// all four corners and taking the outermost values
+	auto const sw = puwg1992(kSouthLatitude, kWestLongitude);
+	auto const se = puwg1992(kSouthLatitude, kEastLongitude);
+	auto const nw = puwg1992(kNorthLatitude, kWestLongitude);
+	auto const ne = puwg1992(kNorthLatitude, kEastLongitude);
+
+	Min = {std::min({sw.x, se.x, nw.x, ne.x}), std::min({sw.y, se.y, nw.y, ne.y})};
+	Max = {std::max({sw.x, se.x, nw.x, ne.x}), std::max({sw.y, se.y, nw.y, ne.y})};
+}
+
+} // namespace editor