Use MobileVLCKit / TVVLCKit to implement dialogs properly in external apps

Use VLCKit to implement dialogs properly in external apps

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

move file inside group

It this flag is set, user interaction will be forced when preparsing the item
given by libvlc_MetaRequest (there won't be user interactions for sub items).

Only callacks are tested by default. In order to test qt dialogs, run the test
manually with './test_src_interface_dialog -a'.

- vlc_dialog_wait_question will replace dialog_Question

- vlc_dialog_wait_question with i_type == VLC_DIALOG_QUESTION_CRITICAL and
  without action1/action2 will replace dialog_FatalWait

- vlc_dialog_wait_login will replace dialog_Login

- vlc_dialog_display_progress will replace dialog_Progress

- dialog_Fatal is replaced by vlc_dialog_display_error

- vlc_dialog_display_error will replace dialog_Fatal

- vlc_ext_dialog_update will repalace dialog_ExtensionUpdate

- vlc_dialog_wait_question and vlc_dialog_wait_login are interruptible via
  vlc_interrupt.

- Nothing prevents to have more than one dialog type displayed at a time.

It'll will be replaced by the new dialog API