KCL: Convert x/y lines to use keyword arguments (#5615)

Previously, `xLine`, `xLineTo`, `yLine` and `yLineTo` used positional arguments. Now:

- `xLineTo` and `yLineTo` have been removed
- `xLine` and `yLine` both use keyword arguments:
  - `length`, optional (i.e. a relative distance along the X or Y axis)
  - `endAbsolute` optional (i.e. an absolute point along the X or Y axis)
  - `tag` optional
- Exactly one of `length` or `endAbsolute` must be given. Not both, not neither.

For example:

```
// Old way
|> xLine(6.04, %)
|> yLineTo(20, %, $base)

// New way
|> xLine(length = 6.04)
|> yLine(endAbsolute = 20, tag = $base)
```

This also improves some of the general-purpose keyword arguments code in modeling app's TS codebase.

src/lib/exampleKcl.ts

@@ -21,11 +21,11 @@ mountingHoleDiameter = 0.5
 
 sketch001 = startSketchOn('XZ')
   |> startProfileAt([0, 0], %)
-  |> xLine(shelfMountL - thickness, %, $seg01)
-  |> yLine(thickness, %, $seg02)
-  |> xLine(-shelfMountL, %, $seg03)
-  |> yLine(-wallMountL, %, $seg04)
-  |> xLine(thickness, %, $seg05)
+  |> xLine(length = shelfMountL - thickness, tag = $seg01)
+  |> yLine(length = thickness, tag = $seg02)
+  |> xLine(length = -shelfMountL, tag = $seg03)
+  |> yLine(length = -wallMountL, tag = $seg04)
+  |> xLine(length = thickness, tag = $seg05)
   |> line(endAbsolute = [profileStartX(%), profileStartY(%)], tag = $seg06)
   |> close()
   |> extrude(%, length = width)