Synchronization to align with the architectural patterns of the inner-circle-items-api repository

[aasheptunov]

Synchronization to align with the architectural patterns of the inner-circle-items-api repository.

User story:
As a developer, I want the architecture of to-dos-api-cpp to align with the patterns implemented in inner-circle-items-api, so that in order to standardize the to-dos-api-cpp repository.

DoD:

• The architecture of to-dos-api-cpp is synchronized with inner-circle-items-api.