feat: add StacVisibility widget

[Abdalqader27]

Description

Introduced the StacVisibility widget, which allows conditional rendering of its child based on a visible property. It also supports maintain properties and a replacement widget.

Examples

• ✅ Example 1: Using Visibility.maintain

{
  "type": "visibility",
  "visible": false,
  "maintainState": true,
  "maintainAnimation": true,
  "maintainSize": true,
  "maintainSemantics": true,
  "maintainInteractivity": true,
  "child": {
    "type": "text",
    "data": "I'm hidden but still take space"
  }
}

• ✅ Example 2: Standard Visibility with replacement

{
  "type": "visibility",
  "visible": false,
  "maintainState": false,
  "maintainAnimation": false,
  "maintainSize": false,
  "maintainSemantics": false,
  "maintainInteractivity": false,
  "child": {
    "type": "text",
    "data": "I'm not visible"
  },
  "replacement": {
      "type": "text",
      "data": "I replace the hidden widget"
  }
}

• ✅ Example 3: Default visible: true

{
  "type": "visibility",
  "child": {
    "type": "text",
    "data": "I'm visible"
  }
}

Related Issues

Closes #263

Type of Change

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)
• Code refactor
• Build configuration change
• Documentation
• Chore

[divyanshub024]

Hey @Abdalqader27 !! Thanks for this PR. Can you please add documentation as well, it's under the website/docs folder?

[Abdalqader27]

Hey @Abdalqader27 !! Thanks for this PR. Can you please add documentation as well, it's under the website/docs folder?

Hey @divyanshub024, I noticed the file here:
https://github.com/StacDev/stac/blob/dev/website/docs/widgets/visibility.md

Would you like me to add more examples to this, or is it sufficient as is?

[divyanshub024]

Ohh, I didn't notice we already had a doc. We are good.

[divyanshub024]

Thanks for the Pr @Abdalqader27 👍🏻
There are few small suggestiong, please check it out.

[divyanshub024]

Thank you for your contribution @Abdalqader27 🎉 💯