Update sql server password to MI

[aponakampalli]

Description

This PR introduces the use of Managed Identity for authentication to SQL Server, eliminating the need for a password in OSS.

Related issues

Addresses issue AB#96639.

Testing

Manual test deployment.

FHIR Team Checklist

• Update the title of the PR to be succinct and less than 65 characters
• Add a milestone to the PR for the sprint that it is merged (i.e. add S47)
• Tag the PR with the type of update: Bug, Build, Dependencies, Enhancement, New-Feature or Documentation
• Tag the PR with Open source, Azure API for FHIR (CosmosDB or common code) or Azure Healthcare APIs (SQL or common code) to specify where this change is intended to be released.
• Tag the PR with Schema Version backward compatible or Schema Version backward incompatible or Schema Version unchanged if this adds or updates Sql script which is/is not backward compatible with the code.
• CI is green before merge
• Review squash-merge requirements

Semver Change (docs)

Patch|Skip|Feature|Breaking (reason)

[brendankowitz]

We also want to update these settings in the Storage resource
From:
https://github.com/microsoft/fhir-server/blob/aa2e70de8031f2b55177a07a7a522ff6317df2d0/samples/templates/default-azuredeploy-docker.json#L631-L646

to

{
            "name": "[variables('storageAccountName')]",
            "type": "Microsoft.Storage/storageAccounts",
            "apiVersion": "2019-06-01",
            "location": "[resourceGroup().location]",
            "properties": {
                "supportsHttpsTrafficOnly": true,
                "allowBlobPublicAccess": false,
                "allowSharedKeyAccess": false
            },
            "condition": "[variables('enableIntegrationStore')]",
            "dependsOn": [],
            "sku": {
                "name": "Standard_LRS"
            },
            "kind": "Storage",
            "tags": {}
        }

[brendankowitz]

As part of deployment we'll need to make some minor edits to this file so we can update CI environment when the PR is merged:

fhir-server/build/ci-deploy.yml

Lines 65 to 74 in ec9f656

	- stage: UpdateRandom
	displayName: 'Determine Random String'
	dependsOn: []
	jobs:
	- job: Password
	pool:
	name: '$(DefaultLinuxPool)'
	vmImage: '$(LinuxVmImage)'
	steps:
	- template: ./jobs/update-sqlAdminPassword.yml

[LTA-Thinking]

We should also make the update Brendan mentioned above to CI deploy.