[bdbarnett]

Fixes #37.

line.set_points(points, n) now takes the same arguments on MicroPython, CircuitPython and CPython: a list or tuple of points (point_precise_t structs or dicts), or a packed buffer.

• CPython used to lower a const T name[] struct-array parameter to a raw pointer, so a list was refused. It now converts a list or tuple into a C array. Because LVGL keeps the pointer (lv_line_set_points never copies), the array, or the buffer you passed, is retained on the widget under a per-function key, the same way string-array arguments already are. A repeat call releases the previous one. This also applies to indev.set_button_points and to grad_init_stops's colours.
• MicroPython and CircuitPython iterated a bytearray element by element as ints. bytes, bytearray and memoryview now pass straight through as the C array, which is what a packed buffer means.

Non-const struct arrays such as lv_obj_transform_point_array, which LVGL writes into, keep the buffer-only lowering on CPython, because a copied list would silently drop those writes.

Test

A new smoke case, test_line_points_list_and_buffer, draws the same line from a list of dicts, a list of structs, a tuple and a packed buffer. It collects garbage before layout, checks that all four give the same size, and checks that a bad item still raises.

Before this change:

• pydevices-lvgl 9.5.52 on CPython: line.set_points rejected a list of dicts: TypeError: Cannot convert 'list' to pointer
• MicroPython unix: line.set_points rejected a packed buffer: SyntaxError: Can't convert int to lv_point_precise_t!

After this change, built locally the way the Linux integration job builds them, the full smoke run passes on:

• MicroPython v1.29.0 unix with lvgl-micropython at its pin
• lvgl-python at its pin, synced from this commit on CPython 3.12, where its unit tests also pass

The generator tests (107) and regenerate_all.sh --check pass. CircuitPython is left to the integration job.