moldable jobspec support

[dongahn]

As part of node-exclusive scheduling for day 1 (flux-framework/flux-sched#833), I submitted a moldable jobspec using flux job submit and got the following error:

  "resources": [
    {
      "type": "node",
      "count": 1,
      "with": [
        {
          "type": "slot",
          "count": 1,
          "with": [
            {
              "type": "core",
              "count": {
                  "min" : 1
              }
            }
          ],
          "label": "task"
        }
      ]
    }
  ],

ahn1@docker-desktop:/usr/src/NODE_X$ 2021-10-29T22:52:09.058711Z job-list.err[0]: parse_res_level: job 6469630033920 invalid jobspec: Expected integer, got object

I looks like there are a few instances that assume non-moldable jobspec:

flux-core/src/modules/job-list/job_state.c

Line 367 in 8bb52a3

"count", &res.count,

flux-core/src/shell/jobspec.c

Line 54 in c9cef24

"count", &res.count,

This handles V1 jobspec correctly, but as we need to extend jobspec to include moldable spec, we need to extend the code as well.

Should I go ahead and propose a change to V1 jobspec RFC PR and use that as a catch-all ticket?