temp/ofono: implement USSD indication in qmimodem driver

Hello, pmOS friends 🙂 Sharing the patch to support USSD QMI indication messages.

As discussed previously here: https://gitlab.com/postmarketOS/pmaports/-/merge_requests/1922#note_511240782 , the best approach to ofono contribution is to upstream the patches. It will also reduce the fragmentation among the distros.

I've worked on KDE plasma-dialer USSD support and it required a new contribution to the ofono too. I've tried to upstream the patch and it's got accepted.

Switching to the latest upstream commit in APKBUILD is not possible yet, since the previous package patches are not synced with the upstream. The same state with Manjaro-ARM, that's why I've decided to share yet another patch 🙂

cc: @lynxis, @JBBgameich, probably also be interested. Someday we will upstream the previous patches and fix this fragmentation issue 🙂