Make Mono_Time an argument to current_time_monotonic

[zugz]

This change is 

[CLAassistant]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[iphydf]

Reviewed 12 of 12 files at r1.
Reviewable status: 0 of 1 approvals obtained (waiting on @zugz)

---

testing/av_test.c, line 568 at r1 (raw file):

    initialize_tox(&bootstrap, &AliceAV, &AliceCC, &BobAV, &BobCC);

    const Mono_Time *mono_time = (*(Messenger **)bootstrap)->mono_time;

// TODO(iphydf): Don't depend on toxcore internals

---

toxav/rtp.c, line 511 at r1 (raw file):

        return session->mcb(session->m->mono_time, session->cs, new_message(&header, length - RTP_HEADER_SIZE,
                            data + RTP_HEADER_SIZE,
                            length - RTP_HEADER_SIZE));

Maybe move this to the line above.

---

toxcore/mono_time.c, line 42 at r1 (raw file):

    monotime->time = 0;
    monotime->base_time = ((uint64_t)time(nullptr) - (current_time_monotonic(monotime) / 1000ULL));

Remove the outer set of parentheses.

---

toxcore/net_crypto.c, line 962 at r1 (raw file):

static int handle_request_packet(const Mono_Time *mono_time, const Logger *log, Packets_Array *send_array,
                                 const uint8_t *data, uint16_t length,
                                 uint64_t *latest_send_time, uint64_t rtt_time)

Move to line above.

[iphydf]

Reviewed 4 of 4 files at r2.
Reviewable status: 1 change requests, 0 of 1 approvals obtained