chore: add support for semantic segmentation models DeeplabV3, LRASPP, FCN

[barhanc]

Description

Adds support for semantic segmentation models DeeplabV3, LRASPP, FCN, both in quantized and FP32 versions.

Introduces a breaking change?

• Yes
• No

Type of change

• Bug fix (change which fixes an issue)
• New feature (change which adds functionality)
• Documentation update (improves or adds clarity to existing documentation)
• Other (chores, tests, code style improvements etc.)

Tested on

• iOS
• Android

Testing instructions

1. Run the computer vision semantic segmentation example app with all added models.
2. Check HF pages for added models in the semantic segmentation collection:
   • https://huggingface.co/software-mansion/react-native-executorch-deeplab-v3
   • https://huggingface.co/software-mansion/react-native-executorch-lraspp
   • https://huggingface.co/software-mansion/react-native-executorch-fcn

Screenshots

Related issues

Closes #799 #830

Checklist

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings

Additional notes