Allow jupyt command and env customization

[chegoryu]

Right now command and env are hardcoded:

ytsaurus/yt/chyt/controller/internal/jupyt/controller.go

Lines 34 to 45 in 82a112d

	func (c *Controller) buildCommand(speclet *Speclet) (command string, env map[string]string) {
	// TODO(max): take port from YT_PORT_0.
	// TODO(max): come up with a solution how to pass secrets (token or password) without exposing them in the
	// strawberry attributes.
	cmd := fmt.Sprintf(
	"bash -x start.sh /opt/conda/bin/jupyter lab --ip '*' --port %v --LabApp.token='' --allow-root >&2", JupytPort)
	return cmd, map[string]string{
	"NB_GID": "0",
	"NB_UID": "0",
	"NB_USER": "root",
	}
	}

Also there is no way to pass environment/secure_vault or add custom patch to spec:

ytsaurus/yt/chyt/controller/internal/jupyt/controller.go

Lines 59 to 80 in 82a112d

	spec = map[string]any{
	"tasks": map[string]any{
	"jupyter": map[string]any{
	"command": command,
	"job_count": 1,
	"docker_image": speclet.JupyterDockerImage,
	"memory_limit": speclet.MemoryOrDefault(),
	"cpu_limit": speclet.CPUOrDefault(),
	"port_count": 1,
	"max_stderr_size": 1024 * 1024 * 1024,
	"user_job_memory_digest_lower_bound": 1.0,
	"environment": env,
	},
	},
	"max_failed_job_count": 10 * 1000,
	"max_stderr_count": 150,
	"title": "JUPYT notebook *" + alias,
	}
	annotations = map[string]any{
	"is_notebook": true,
	"expose": true,
	}

I have ugly workaround with custom docker image:

RUN mv /usr/local/bin/start.sh /usr/local/bin/real_start.sh
COPY my_start.sh /usr/local/bin/start.sh

Where I replace entrypoint command like this:

NB_USER=jovyan NB_UID=1000 NB_GID=100 PATH='/opt/conda/bin:/opt/conda/condabin:/opt/conda/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/spark/bin' real_start.sh run-one-constantly jupyter lab --ip '*' --port 27042 '--NotebookApp.password=argon2:$argon2id$...' --ResourceUseDisplay.cpu_limit=32 --ResourceUseDisplay.mem_limit=128000000000 >&2

But the disadvantages of this are obvious:

1. Password is hardcoded (and its hash is exposed), so I need different docker images for different users
2. I can't change anything without rebuilding docker image