snap-store-assertions needs to be shortened in 'juju model-config'

[John A Meinel]

We do something similar with cloudinit-userdata, where when it is set we just report:
$ juju model-config
...
cloudinit-userdata model <value set, see juju model-config cloudinit-userdata>
...

and we give the proper content if you ask for it directly:
$ juju model-config cloudinit-userdata

however, 'snap-store-assertions' is also a very large text content (it takes approx 2 screens to show and is mostly hex. eg:
snap-store-assertions controller |
  type: account-key
  authority-id: canonical
  revision: 2
  public-key-sha3-384: BWDEoaqyr25nF5SNCvEv2v7QnM9QsfCc0PBMYD_i2NGSQ32EF2d4D0hqUel3m8ul
  account-id: canonical
  name: store
  since: 2016-04-01T00:00:00.0Z
  body-length: 717
  sign-key-sha3-384: -CvQKAwRQ5h3Ffn10FILJoEZUXOv6km9FwA80-Rcj-f-6jadQ89VRswHNiEB9Lxk

  AcbBTQRWhcGAARAA0KKYYQWuHOrsFVi4p4l7ZzSvX7kLgJFFeFgOkzdWKBTHEnsMKjl5mefFe9ji
...

(and that continues for another couple pages.

Just folding it away as "<value set, ..." seems quite useful so it doesn't disrupt the normal "juju model-config" overview.

[Canonical Juju QA Bot (juju-qa-bot)]

This bug has not been updated in 2 years, so we're marking it Low importance. If you believe this is incorrect, please update the importance.