Create an initial mock bank (ASPSP) SpringBoot project for Open Banking

Story

As a TPP I want to be able to test my application against a bank simulator so that I can be assured my application will work against a real ASPSP

The mock bank supports v3.0 onwards of the Open Banking Read/Write REST API.
The mock bank does not authenticate or authorise the client - any client with appropriate network access can send/receive HTTP requests/responses.
Open Banking API objects are converted to FR domain objects and stored in mongo.

List of tasks required to implement this story

[x] Create initial SpringBoot maven based project with the groupId com.forgerock.sba.aspsp and artifactId forgerock-sba-mock-aspsp.
[x] Port "common" code (e.g. repositories, mongo document classes, FR domain model and converters) from openbanking-aspsp.
[x] Copy the required snippets of code from openbanking-openbanking-model, thereby allowing a self contained project.
[x] Refactor the package structure, making the separation of layers more obvious.
[x] Use embedded MongoDB for SpringBoot tests, rather than docker-compose.
[x] Generate the OB model objects within this project (e.g. as a sub-module).
[x] Add a simple example controller for the payments API (to prove the project works end-to-end using postman).

Affected App: forgerock-sba-mock-aspsp