Monitor incoming trades

[Abrynos]

Checklist

• I read and understood the Contributing Guidelines.
• This is not a duplicate of an existing merge request.
• I believe this falls into the scope of the project and should be part of the built-in functionality.
• My code follows the code style of this project.
• I have added tests to cover my changes, wherever they are necessary.
• All new and existing tests pass.

Changes

As requested on our community Discord server.

New functionality

Metrics endpoint now provides information about trades received since last ASF restart.

Changed functionality

None

Removed functionality

None

Additional info

I do not want to include too much information (e.g. which items [marketable, rarity, appid, type, assetid, classid, contextid] were traded) due to performance/memory considerations. As soon as we start adding those details, this will quickly get out of hand.

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Thank you for considering the inclusion of this merge request.

[Abrynos]

Draft, as I am not completely sure about this feature. Waiting for feedback before marking as ready for review.

[JustArchi]

Use post-increment AcceptedOffers++ if you don't need pre-increment, like here, it's more readable imo. Every single sane compiler optimizes it in the same way since decades.

[Abrynos]

I write it this way out of habit and to be honest I'm too lazy to change this now. If it's that important to you, I'll do it, but I'd say it's a quite superfluous change.

[JustArchi]

It's important for me to have consistency across ASF repository, so yeah, it is important to me - but I can do it myself post-PR if needed.

[JustArchi]

This is probably misleading, a donation trade offer will be Confirmed despite no confirmation being needed, even for people without 2FA.

Consider automatically_confirmed, accepted_and_confirmed, confirmed or something similar instead.

[Abrynos]

I'm not sure what you mean exactly. Can you elaborate?

[JustArchi]

I'm not sure what you mean exactly. Can you elaborate?

2fa_confirmed name.