Add handling for circle EURC offramping

[prayagd]

Context

The circle EURC offramp has different anchor endpoint in order to support circle EURC offramping, we need to hit the new end point i.e https://circle.anchor.mykobo.co/

Requirements

• Hardcode the anchor endpoint for Circle EURC to https://circle.anchor.mykobo.co/
• Ideally check the issuer of the Stellar EURC used by the Nabla deployment to determine the anchor endpoint

[prayagd]

Hey team! Please add your planning poker estimate with Zenhub @ebma @gianfra-t @TorstenStueber

[TorstenStueber]

@prayagd I propose that we close this ticket and instead add it as an additional requirement to https://github.com/pendulum-chain/vortex/issues/98.

After all, these changes need to be rolled out atomically, all at once.

[prayagd]

Closing this as copied over the requirements to #98