Azure CLI Synapse Workspace should be able to activate a workspace

When a Synapse Workspace is created and encryption activated, users have to give the managed identity of the workspace permissions to access the key, and then return to the workspace to do the manual step of activating it. There does not seem to be an AZ Cli command for activating the workspace in this circumstance.

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#### Document Details

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* ID: 9f78ab1c-455b-1c48-1ff1-7b8b5308aa11
* Version Independent ID: 72f4f56d-5b08-6cec-3cb0-981db572e524
* Content: [az synapse workspace](https://docs.microsoft.com/en-us/cli/azure/synapse/workspace?view=azure-cli-latest)
* Content Source: [latest/docs-ref-autogen/synapse/workspace.yml](https://github.com/MicrosoftDocs/azure-docs-cli/blob/master/latest/docs-ref-autogen/synapse/workspace.yml)
* GitHub Login: @rloutlaw
* Microsoft Alias: **routlaw**