Add the Alert component

[albx]

Create a reusable Razor component for alerts, adhering to the guidelines and styles provided by Bootstrap Italia - Alerts. The component should support all standard alert variants, dismissible functionality, and custom content as described in the documentation.

Requirements:

• Implement a Razor component (e.g., BitAlert.razor) that encapsulates the Bootstrap Italia alert styles.
• Support all color variants (primary, secondary, success, danger, warning, info, light, dark, etc.).
• Enable dismissible/closable alerts.
• Allow for custom content (text, icons, links, etc.) inside the alert.
• Expose parameters for accessibility and ARIA attributes.
• Ensure accessibility best practices are followed.
• Add XML documentation for all public parameters.

Acceptance Criteria:

• The component renders valid Bootstrap Italia alert markup.
• All documented variants are supported via parameters.
• The component is unit tested for all major variants and features.
• Usage examples are provided in the documentation or a sample page.

References:

• Bootstrap Italia - Alerts Documentation