Feature: find_apps support customer app class (RDT-589)

[ydc-0]

I needs some specific features in my project:

• Building eco versions with different folder names
• Pre process magic sdkconfig files

I was able to achieve them in this way with this PR:

class MyApp(CMakeApp):
    ECO_VERSION_PLACEHOLDER = '@e'  # replace it with the ECO version
    _eco: str

    def __init__(self, *args, **kwargs):
        if 'eco' not in kwargs:
            kwargs['eco'] = ''
        super().__init__(*args, **kwargs)

    def _initialize_hook(self, **kwargs):
        self._eco = kwargs['eco']

    def _expand(self, path: str) -> str:
        path = super()._expand(path)
        return path.replace(self.ECO_VERSION_PLACEHOLDER, self._eco)

    def _process_sdkconfig_files(self):
        import jinja2
        ...
        pass


apps = find_apps('xxx', build_system=MyApp, xxx)
apps = _filter_or_duplicate(apps)
build_apps(apps, xxxx)

[hfudev]

LGTM! Thank you for your PR @xd-ydchen

[hfudev]

Thank you @xd-ydchen !