WIP: Move platform specific modules out of eavmlib

[bettio]

Move emscripten, esp and pico modules to their own library.

These changes are made under both the "Apache 2.0" and the "GNU Lesser General Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later