Request to change - Business Critical references to Memory Optimized

### Preconditions

- [x] No need to upgrade Python SDK or the Python SDK is ready.

### Related command

_No response_

### Resource Provider

Azure MySQL

### Description of Feature or Work Requested

Business Context - We have renamed “Business Critical” back to “Memory Optimized” to clearly convey the tier’s value (optimized for memory-intensive, performance-critical workloads) and align with naming conventions used in MySQL and other OSS database services. This change will emphasize technical accuracy over market branding, addressing customer feedback and reducing confusion. The renaming will not alter any functionality or pricing – it is a label change only, with all tier capabilities remaining intact. **And therefore, we need to have these updates in CLI documentation as well.**

**Example of change required:**
1. https://learn.microsoft.com/en-us/cli/azure/mysql/flexible-server?view=azure-cli-latest#az-mysql-flexible-server-create-optional-parameters
Original Text - "Enable or disable accelerated logs. Only support for Business Critical tier. Default value is Enabled."
Updated Text Required - "Enable or disable accelerated logs. Only support for Memory Optimized. Default value is Enabled."

**Key Ask-**
1. Scan through all the pages for Azure MySQL - https://learn.microsoft.com/en-us/cli/azure/mysql?view=azure-cli-latest#commands
2. Replace Business Critical to **Memory Optimized** in all text references.

### Minimum API Version Required

NA

### Swagger PR link / SDK link

NA

### Request Example

_No response_

### Target Date

asap

### PM Contact

vamehta@microsoft.com

### Engineer Contact

haoranhong@microsoft.com

### Additional context

_No response_