refactor: improve cast and hooks management

[flower-of-the-bridges]

Pull Request Type

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, local variables)
• [x] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [ ] Documentation content changes
• [ ] Other... Please describe:

Description

This PR introduces the following refactor changes:

• hooks and serializer compiler are not registered anymore on every httpInterface.js, but only once in index.js, to avoid multiple registers for collections
• validator compiler is still applied to each HTTP interface to avoid OOM, but it has been moved to compilers.js
• AdditionalCaster class does not need anymore to compute the fields that are either ObjectId, Date, or Geopoint at startup: in the new castItem method, field types are inferred using the instanceof keyword.
• there are only 2 Ajv instances registered at runtime, while at startup there is an ajv instance for each collection to validate the json schema

Also, the following bug due to updating dependencies has been fixed:

• serializerCompiler has been added to use fastifiy-fast-json, along with AdditionalCaster explicitly

Plus, for code styling, a .eslintrc.js file has been added, and its content has been moved from the configuration used within package.json

PR Checklist

• [x] The commit message follows our guidelines included in the CONTRIBUTING.md
• [x] Tests for the changes have been added (for bug fixes / features)
• [x] Docs have been added / updated (for bug fixes / features)

Does this PR introduce a breaking change?

• [ ] Yes
• [x] No

Other information