[Feature]: Support for Content Hub Solutions

### Description of the new feature

The latest Az.SecurityInsights module has no support for anything related to the solutions in the content hub. The following features would be helpful

- Get available content hub solutions
- Install content hub solutions
- Update content hub solutions

In addition, with the forced move to content hub solutions last year, the Get-AzSentinelAlertRuleTemplate cmdlet doesn't return results that match the portal. This cmdlet doesn't seem to respect which versions of the template are actually available based on the installed solutions. We either need new functionality in this cmdlet or a separate cmdlet that uses the contenttemplates REST API to find the available rule templates. There may be similar inconsistencies in other areas, but this is all I'm familiar with.

### Proposed implementation details (optional)

_No response_

Start by reviewing the Az.SecurityInsights module and Get-AzSentinelAlertRuleTemplate, then compare its behavior with the contenttemplates REST API and installed content hub solutions. Define the required interfaces for listing, installing, and updating solutions, plus how available rule templates should be filtered. Done means the requested solution operations work and template results match the portal.

Written by the indexing model from the issue text.