Pdf refactoring

[SergeShkurko]

Package [native_pdf_renderer] v5.0.0

• Rename and publish as [pdf_renderer]
• iOS and macOS use a single codebase
• Provide docs for network pdf usage
• Usage [plugin_platform_interface] for better work web

Usage [pigeon] on

• iOS & macOS
• Android

Texture rendering (#6) on

• iOS & macOS
• Android
• Web

Package [native_pdf_view] v6.0.0

• Usage texture rendering ([native_pdf_view] Add Zooming without pixel loss #6)
• Added vertical view
• Provide page counter builder
• Provide docs for [native_pdf_view] Hotkey zoom in a PDF View #84
• Provide docs for network pdf usage

[rohan-tide]

Any inputs on when this PR will be merged and a new version will be released?