## Checklist
- [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md)
- [x] reference issue for this pull request: https://github.com/ooni/probe/issues/1885
- [x] related ooni/spec pull request: N/A
Location of the issue tracker: https://github.com/ooni/probe
## Description
This PR contains a set of changes to move important interfaces and data types into the `./internal/model` package.
The criteria for including an interface or data type in here is roughly that the type should be important and used by several packages. We are especially interested to move more interfaces here to increase modularity.
An additional side effect is that, by reading this package, one should be able to understand more quickly how different parts of the codebase interact with each other.
This is what I want to move in `internal/model`:
- [x] most important interfaces from `internal/netxlite`
- [x] everything that was previously part of `internal/engine/model`
- [x] mocks from `internal/netxlite/mocks` should also be moved in here as a subpackage
Adapt other places where it was not using a logger to either choose
a reasonable logger or disable logging for backwards compat.
See https://github.com/ooni/probe/issues/1591
With this change, we are now able to change more dependent code to simplify
the way in which we create and manage resolvers.
See https://github.com/ooni/probe/issues/1591
With this factory, we want to construct ourselves the TLS dialer
so that we can use a dialer wrapper that always sets timeouts when
reading, addressing https://github.com/ooni/probe/issues/1609.
As a result, we cannot immediately replace the i/e/netx factory
for creating a new HTTP transport, since the functions signatures
are not directly compatible.
Refactoring is part of https://github.com/ooni/probe/issues/1505.
This diff is part of https://github.com/ooni/probe/issues/1505.
You will notice that I have not adapted all the (great) tests we had
previously. They should live at another layer, and namely the one that
deals with performing measurements.
When I'm refactoring such a layer I'll ensure those tests that I have
not adapted here are reintroduced into the tree.
