feat: ion-button icon slot top and bottom

[Spinnenzunge]

Prerequisites

• [x] I have read the Contributing Guidelines.
• [x] I agree to follow the Code of Conduct.
• [x] I have searched for existing issues that already include this feature request, without success.

Describe the Feature Request

Adding support for ion-icon slot top and bottom for Multi-Line Buttons with Icons on Top or Bottom.

Describe the Use Case

Describe Preferred Solution

Adding slot for bottom and top to support design described in Use Case

Describe Alternatives

No response

Related Code

No response

Additional Information

No response