Moved delayhook to phlib

[DartVanya]

• phlib PhIsThemeSupportEnabled, exported for plugins.
• New option EnableThemeUseWindowsTheme - Use Windows app color mode. On default settings PH will use current Windows theme.
• New option EnableThemeTabBorders (default 0).

Theme switches use this logic:

BOOLEAN PhIsThemeSupportEnabled(
    VOID
    )
{
    if (PhGetIntegerSetting(L"EnableThemeSupport"))
    {
        if (PhGetIntegerSetting(L"EnableThemeUseWindowsTheme"))
            return PhShouldAppsUseDarkMode();
        else
            return TRUE;
    }
    else
    {
        return FALSE;
    }
}

EnableThemeUseWindowsTheme.mp4