nixos/tsm-client: add migration code for freeform settings

To help users migrate from the previous
settings to new freeform settings type,
the commit at hand adds some
`mkRemovedOptionModule` and `mkRenamedOptionModule`.

These modules are not designed to work
inside an attribute set of submodules.
They create values for `assertions` and
`warnings` to inform the user of required changes.
Also, these informational texts do not contain
the full attribute path of the changed options.
To work around these deficiencies,
we define the required options `assertions` and `warnings`
inside the submodule and later add the values collected
inside these options to the corresponding top-level options.
In the course of doing so, we also add the full attribute path
to the informational texts so the user knows these warning
and error messages refer to the `tsmClient.servers` option.

Also, we have to filter out `warnings`, `assertions`, and
the "old" options when rendering the target config file.

0 files changed, 0 insertions, 0 deletions