FINERACT-2169: Account rules api refactor;

[VictorPavfurious]

Description

1. Replace string req/responce to dto;
2. Improve code styles;

Checklist

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• Add required Swagger annotation and update API documentation at fineract-provider/src/main/resources/static/legacy-docs/apiLive.htm with details of any API changes

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[adamsaghy]

Kindly review whether the response data type and the swagger responses are matching or not!

Alternatively we can remove all the explicit swagger classes and let the system generate the swagger response based on the response data type!