Epsilon: native support

[johnwier]

🔧 Type of changes

• [ ] new bid adapter
• [x] bid adapter update
• [ X ] new feature
• [ ] new analytics adapter
• [ ] new module
• [ ] module update
• [ ] bugfix
• [ ] documentation
• [ ] configuration
• [ ] dependency update
• [ ] tech debt (test coverage, refactorings, etc.)

✨ What's the context?

Update the Epsilon bid adapter to allow Native requests This is a port from PBS https://github.com/prebid/prebid-server/pull/4277

🧠 Rationale behind the change

Why did you choose to make these changes? Were there any trade-offs you had to consider?

🔎 New Bid Adapter Checklist

• [ ] verify email contact works
• [ ] NO fully dynamic hostnames
• [ ] geographic host parameters are NOT required
• [ ] direct use of HTTP is prohibited - implement an existing Bidder interface that will do all the job
• [ ] if the ORTB is just forwarded to the endpoint, use the generic adapter - define the new adapter as the alias of the generic adapter
• [ ] cover an adapter configuration with an integration test

🧪 Test plan

How do you know the changes are safe to ship to production?

🏎 Quality check

• [ ] Are your changes following our code style guidelines?
• [ ] Are there any breaking changes in your code?
• [ ] Does your test coverage exceed 90%?
• [ ] Are there any erroneous console logs, debuggers or leftover code in your changes?

[AntoxaAntoxic]

Is it a port from PBS-Go? If yes, please link the PR.

[johnwier]

This is a port from PBS https://github.com/prebid/prebid-server/pull/4277

[johnwier]

Not sure if it's a significant issue, but in PBS-Java, epsilon is the base bidder with conversant as its alias, whereas in PBS-Go, it's the other way around.

This is related to #2654 It started as conversant and was changed to epsilon. As long as both names work I'm ok with it.

[AntoxaAntoxic]

@johnwier do you have any problems with tackling the comments? feel free to ask us anything that could be helpful for you

[osulzhenko]

@johnwier any updates on this one?