[Module Proposal]: `avm-res-fabric-capacity`

### Check for previous/existing GitHub issues/module proposals

- [x] I have checked for previous/existing GitHub issues/module proposals.

### Check this module doesn't already exist in the module indexes

- [x] I have checked for that this module doesn't already exist in the module indexes.

### Bicep or Terraform?

Terraform

### Module Classification?

Resource Module

### Module Name

avm-res-fabric-capacity

### Module Details

This Terraform module will automate Microsoft Fabric Capacity deployments on Azure. The module will leverage both AzureRM provider for core resource and Fabric provider for specific features.

As an official Azure Verified Module, it will include comprehensive input validation, telemetry options, and enterprise-ready security configurations.

### Do you want to be the owner of this module?

Yes

### Module Owner's GitHub Username (handle)

DariuszPorowski

### (Optional) Secondary Module Owner's GitHub Username (handle)

Halamish51