[Feature Request]: ARM Template/Bicep for Synapse Linked Services

### Description

## Problem:
- At the moment, ARM templates (and Bicep) cannot be used to create **linked services** in [Synapse workspaces](https://docs.microsoft.com/en-us/azure/templates/microsoft.synapse/workspaces?pivots=deployment-language-bicep).
- Currently, the only way to create linked services is through Synapse Analytics web dashboard or [az synapse CLI](https://docs.microsoft.com/en-us/cli/azure/synapse/linked-service?view=azure-cli-latest)
- This is particularly important in linking key vaults, storage accounts or logAnalytics to synapse workspace by using arm templates/bicep

## Similar implementations:
- [Data factory linked services](https://docs.microsoft.com/en-us/azure/templates/microsoft.datafactory/factories/linkedservices)

## Workarounds:
I am aware currently there are workarounds such as:
- Deploy synapse workspace/storage account/key vault through arm templates and then
- Use Synapse CLI to link the services

However, the fact that this won't be a streamlined experience could decrease development experience and quality long term-wise.

## Relevant discussions:
- [Stackoverflow](https://stackoverflow.com/questions/70936838/arm-template-bad-request-failed-when-deploying-a-linked-service?answertab=createdasc#tab-top)
- [Microsoft discussion forum](https://feedback.azure.com/d365community/idea/05e41bf1-0925-ec11-b6e6-000d3a4f07b8)
- [Microsoft discussion forum](https://feedback.azure.com/d365community/idea/48f1bf78-2985-ec11-a81b-6045bd7956bb)