Change `DTLSTransport` to a process

[LVala]

Tests will be added, when ExDTLS is replaced with the new, module-based one. Also, demuxing is still, for the time being, in PeerConnection.

[codecov[bot]]

Codecov Report

Merging #16 (3a9380b) into master (9a03882) will decrease coverage by 0.17%. The diff coverage is 34.78%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #16 +/- ## ========================================== - Coverage 74.63% 74.47% -0.17% ========================================== Files 10 10 Lines 414 427 +13 ========================================== + Hits 309 318 +9 - Misses 105 109 +4 ``` | [Files](https://app.codecov.io/gh/elixir-webrtc/ex_webrtc/pull/16?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc) | Coverage Δ | | |---|---|---| | [lib/ex\_webrtc/peer\_connection.ex](https://app.codecov.io/gh/elixir-webrtc/ex_webrtc/pull/16?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc#diff-bGliL2V4X3dlYnJ0Yy9wZWVyX2Nvbm5lY3Rpb24uZXg=) | `76.33% <61.53%> (+3.18%)` | :arrow_up: | | [lib/ex\_webrtc/dtls\_transport.ex](https://app.codecov.io/gh/elixir-webrtc/ex_webrtc/pull/16?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc#diff-bGliL2V4X3dlYnJ0Yy9kdGxzX3RyYW5zcG9ydC5leA==) | `33.33% <28.57%> (+3.33%)` | :arrow_up: | ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/elixir-webrtc/ex_webrtc/pull/16?src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/elixir-webrtc/ex_webrtc/pull/16?src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc). Last update [9a03882...3a9380b](https://app.codecov.io/gh/elixir-webrtc/ex_webrtc/pull/16?src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=elixir-webrtc).

[mickel8]

To be discussed:

• how to name processes for easier observability in :observer
• should we spawn DTLS transport and ICE agent under supervisor?

I created a sample app that spawn PeerConnection. The diagram from the observer looks like this:

0.245 is PC 0.246 is DTLSTransport 0.249 is ICEAgent