network: Improve service recommended bitrate check

[Penwy]

Description

This simplifies the services recommended bitrate check, and allows it to function properly if there's more than one encoding session.
It also fixes the potential issue of the stream encoding session not having a bitrate, or not logging it as expected.

Motivation and Context

This was motivated by seeing the check fire from a recording session's bitrate instead of the stream's bitrate (log in question https://obsproject.com/logs/zGyyE5KFzk1b4KCT).

How Has This Been Tested?

Tested with manually created logs of every possible case I could think of.

Types of changes

• Tweak (non-breaking change to improve existing functionality)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[RytoEX]

Per #185, log https://obsproject.com/logs/3zpBZBLcluZG6A3Q breaks with an error.

[Penwy]

fixed, had forgotten the ignore message still shows up with TEB active.
Took the opportunity to fix a few other possible breakages, shorten the searches, and add a few comments on the bits in it that aren't too trivial on what they do.

[RytoEX]

Prefix should be "network: ".