[Synapse] Add new cmdlets related to SQL rule baseline and sensitivity on Synapse SQL pool

[idear1203]

Description

Design review link: https://github.com/Azure/azure-powershell-cmdlet-review-pr/issues/798

Differences with the design review:

• SqlPoolName now is an alias of Name parameter for the following commands in order to keep align with Az.Sql cmdlets:
  • Get-AzSynapseSqlPoolVulnerabilityAssessmentSetting
  • Reset-AzSynapseSqlPoolVulnerabilityAssessmentSetting
  • Update-AzSynapseSqlPoolVulnerabilityAssessmentSetting
• Remove default parameter set for *-AzSynapseSqlPoolVulnerabilityAssessmentRuleBaseline to keep align with SQL's original cmdlets. For example, Set-AzSqlDatabaseVulnerabilityAssessmentRuleBaseline doesn't have a default parameter set.

Changes:

• Added support for operation of Data Classification in SqlPool-level
  • Add Disable-AzSynapseSqlPoolSensitivityRecommendation cmdlet
  • Add Enable-AzSynapseSqlPoolSensitivityRecommendation cmdlet
  • Add Get-AzSynapseSqlPoolSensitivityRecommendation cmdlet
  • Add Get-AzSynapseSqlPoolSensitivityClassification cmdlet
  • Add Remove-AzSynapseSqlPoolSensitivityClassification cmdlet
  • Add Set-AzSynapseSqlPoolSensitivityClassification cmdlet
• Added support for operation of Vulnerability Assessment Baseline in SqlPool-level
  • Add Clear-AzSynapseSqlPoolVulnerabilityAssessmentRuleBaseline cmdlet
  • Add Get-AzSynapseSqlPoolVulnerabilityAssessmentRuleBaseline cmdlet
  • Add Set-AzSynapseSqlPoolVulnerabilityAssessmentRuleBaseline cmdlet

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
    • {Please put the link here}
  • the markdown help files have been regenerated using the commands listed here