Prepare for 2.1.0 release

[TimPurdum]

Release Notes

Features

• Added ToMap and ToScreen point conversions to MapView.razor.cs
• Added methods to control PopupWidget visibility and read feature sets

Large Graphic Data Sets

• Move all graphic collection serialization from .NET to JavaScript to Protobuf from JSON
• Tested and adjusted graphic-handling code for WASM, Server, and MAUI scenarios
  • use synchronous JavaScript interop in WASM
  • use multi-threaded async loading in Server

Bug Fixes

• Fixed relative asset path impacted by route parameters
• Fixed bug in setting xoffset and yoffset for marker symbols
• Fixed bug with setting UniqueValueRenderer

Documentation

• Improved documentation and sample of MAUI configuration loading and Android emulator issue