feat(CLI): envd create command

[gaocegege]

Description

envd create will be introduced as the new command. It builds the image and launches the container/pod. If the runner is envd-server, the image needs to be pushed first.

Here, the endpoint from envd-server needs to be designed carefully.

POST /v1/environments
To be determined.

And, the pod name should be searchable. The envd-server needs to find the correct pod from the limited information (identity token and project name) when users run ssh.

Ref #303 #939

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[gaocegege]

And, in the issue, we need to refactor the func StartEnvd() in the engine interface.

[gaocegege]

We will implement pod creation first:

envd create --image=xxx

It's optional.