feat: add SvgImage widget

[Abdalqader27]

Description

• Introduced a new SvgImage widget to the Stac framework.
• Added StacSvgImage model with support for asset, network, file, memory, and string sources.
• Implemented StacSvgImageParser to parse JSON and render SvgPicture widgets.
• Added StacColorFilter model for applying color filters to SVGs.
• Introduced StacBytes class for handling byte arrays with Base64 encoding/decoding.
• Updated pubspec.yaml to include flutter_svg dependency.
• Registered StacSvgImageParser in the Stac framework.
• Added svgImage to WidgetType enum.

Examples

1. SVG Asset with colorFilter

{
  "type": "svgImage",
  "subtype": "asset",
  "asset": "assets/icons/sample.svg",
  "width": 100,
  "height": 100,
  "semanticsLabel": "Sample SVG Asset",
  "matchTextDirection": true,
  "colorFilter": {
    "filterType": "mode",
    "color": "#FF0000",
    "blendMode": "srcIn"
  }
}

2. SVG Network with colorFilter

{
  "type": "svgImage",
  "subtype": "network",
  "url": "https://example.com/image.svg",
  "width": 120,
  "height": 120,
  "semanticsLabel": "Network SVG",
  "matchTextDirection": false,
  "colorFilter": {
    "filterType": "mode",
    "color": "#00FF00",
    "blendMode": "multiply"
  }
}

3. SVG File without colorFilter

{
  "type": "svgImage",
  "subtype": "file",
  "path": "/storage/emulated/0/Download/image.svg",
  "width": 150,
  "height": 150,
  "semanticsLabel": "Local file SVG",
  "matchTextDirection": false
}

4. SVG Memory with matrix colorFilter

{
  "type": "svgImage",
  "subtype": "memory",
  "bytes": "base64encodeddata==",
  "width": 80,
  "height": 80,
  "semanticsLabel": "Memory SVG",
  "matchTextDirection": false,
  "colorFilter": {
    "filterType": "matrix",
    "matrix": [
      1, 0, 0, 0, 0,
      0, 1, 0, 0, 0,
      0, 0, 1, 0, 0,
      0, 0, 0, 1, 0
    ]
  }
}

5. SVG String with linearToSrgbGamma colorFilter

{
  "type": "svgImage",
  "subtype": "string",
  "svgString": "<svg>...</svg>",
  "width": 50,
  "height": 50,
  "semanticsLabel": "String SVG",
  "matchTextDirection": true,
  "colorFilter": {
    "filterType": "linearToSrgbGamma"
  }
}

Related Issues

Closes #265

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, I'm sorry, but we can't merge this PR. @Potatomonsta is already working on it. And we don't want to create a new widget for this. We want to incorporate Svg in the old image PR.

[Abdalqader27]

Hey @Abdalqader27, I'm sorry, but we can't merge this PR. @Potatomonsta is already working on it. And we don't want to create a new widget for this. We want to incorporate Svg in the old image PR.

Hey @divyanshub024 There isn’t clear documentation or an assigned owner for this, which is why I proceeded to create it. However, no problem at all.

[divyanshub024]

Hey @Abdalqader27, sorry it's my bad. I'll make sure there is better documentation around it.