Color management: commands reject a param of the wrong type

The color management commands read their params with helpers that fell
back to the default for a value of the wrong type, so "bpc": "no" kept
the old setting, "on": "true" toggled the view and "convert": "no"
converted the colors. They now go through switch_or and text_param:
such a value is an error and nothing changes. Omitting a param or
giving null keeps its default.

- edit.colorSettings: rgb, cmyk, intent, bpc
- file.documentColorMode (and its alias): convert, intent, grays,
  checked before the early return for the current mode; PDF import's
  grays reads the same way
- color.convert: to, intent
- color.loadProfile: path; color.removeProfile: name
- view.proofSetup: target, intent, simulatePaper, proof
- view.proofColors and view.overprintPreview: on
- view.separationsPreview: on, only, toggle, and plates, which must be
  an array of plate names
- swatch.setSpot: name, spot

docs/mcp.md

@@ -662,6 +662,10 @@ them. `grays: "black"` puts RGB greys with R = G = B on the black plate instead,
 Convert to Grayscale before the switch would give); other colors convert as usual. The reply's `changed` counts the
 colors that changed in the art, symbols, graph designs and pattern tiles; it does not count the colors of graphic
 styles and brushes.
+`edit.colorSettings`, `file.documentColorMode`, `color.convert`, `color.loadProfile`, `color.removeProfile`,
+`view.proofSetup`, `view.proofColors`, `view.overprintPreview`, `view.separationsPreview` and `swatch.setSpot` reject a
+param of the wrong type, such as `"bpc": "no"`, `"on": 1` or `"to": 5`, and change nothing. Omitting a param or giving
+null keeps its default.
 
 SVG import keeps what the canvas edits live. `<pattern>` becomes a pattern swatch. A `<symbol>` with `<use>` becomes a
 symbol (named after its `data-name`, else its id) with an instance per `<use>`; a `<use>` that shows it differently