chore: add a 'backend mock server' to ease frontend development

[tbouffard]

This mock server provides the same API as the real backend. It is powered by the NestJS framework. All http requests are logged thanks to the pino-http library. There is no need to have XES local file when using the mock server: it returns arbitrary data.

Notes: the following APIs are available, but they need to be improved to allow a correct display in the frontend:

• conversion/xes-to-csv
  • conformance/alignment

closes #18

Screenshots

Notes

NestJS: https://nestjs.com/ source inspiration for the pino configuration: https://getpino.io/#/ and https://www.tomray.dev/nestjs-logging

Improvements that could follow

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