## Description
This PR continues the refactoring of `netx` under the following principles:
1. do not break the rest of the tree and do not engage in extensive tree-wide refactoring yet
2. move under `netxlite` clearly related subpackages (e.g., `iox`, `netxmocks`)
3. move into `internal/netxlite/internal` stuff that is clearly private of `netxlite`
4. hide implementation details in `netxlite` pending new factories
5. refactor `tls` code in `netxlite` to clearly separate `crypto/tls` code from `utls` code
After each commit, I run `go test -short -race ./...` locally. Each individual commit explains what it does. I will squash, but this operation will preserve the original commit titles, so this will give further insight on each step.
## Commits
* refactor: rename netxmocks -> netxlite/mocks
Part of https://github.com/ooni/probe/issues/1591
* refactor: rename quicx -> netxlite/quicx
See https://github.com/ooni/probe/issues/1591
* refactor: rename iox -> netxlite/iox
Regenerate sources and make sure the tests pass.
See https://github.com/ooni/probe/issues/1591.
* refactor(iox): move MockableReader to netxlite/mocks
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): generator is an implementation detail
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): separate tls and utls code
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): hide most types but keep old names as legacy
With this change we avoid breaking the rest of the tree, but we start
hiding some implementation details a bit. Factories will follow.
See https://github.com/ooni/probe/issues/1591
This diff breaks the circular dependency between session and
tunnel, by introducing the concept of early session.
An early session is a session that is able to fetch the psiphon
configuration file _only_ if it's embedded in the binary.
This breaks `miniooni --tunnel=psiphon` for users who have
access to the OONI backend. They are not the users we are
writing this feature for, though, so I think this is reasonable.
At the same time, this opens up the possibility of creating
a psiphon tunnel when constructing a session, which is the
approach I was following in https://github.com/ooni/probe-cli/pull/286.
This work is part of https://github.com/ooni/probe/issues/985.
Once this diff is in, I can land https://github.com/ooni/probe-cli/pull/286.
We use an optional build tag to hide this configuration. When you
choose this configuration, you need to provide the encrypted config
as well as the corresponding decryption key.
This is not the final design. This is an interim design to start
working and experimenting with this functionality. The general
idea here is to support psiphon in the binaries we build without
committing the psiphon config to the repository itself.
Part of https://github.com/ooni/probe/issues/985
