feat: add the capability to override the docker cli and arguments

[sebasmagri]

In environments that don't provide the docker command, or in which it is on a different path, the variable SLS_DOCKER_CLI can be used to override the default, and the SLS_DOCKER_ARGS can be used to set additional parameters for the run subcommand as needed.

For example, in environments which provide podman instead:

$ SLS_DOCKER_CLI=podman serverless invoke ...

[sebasmagri]

@softprops let me know what you think of this and if I should add this to the changelog

[softprops]

Looks good @sebasmagri

[sebasmagri]

@softprops any chance to get this released?

[softprops]

Sorry for the lag on this. I'll try to get to that at lastest by next weekend. I'll update this thread when I do

[sebasmagri]

Hey @softprops! Any way I can help getting this thru? Best Regards,