Move Wasmtime for .NET to the Wasmtime repo.

This moves the Wasmtime for .NET implementation to the Wasmtime repo.

Wasmtime for .NET is a binding of the Wasmtime API for use in .NET.

crates/misc/dotnet/tests/Modules/TableImports.wat

@@ -0,0 +1,5 @@
+(module
+  (import "" "table1" (table $t1 10 funcref))
+  (import "" "table2" (table $t2 15 anyref))
+  (import "other" "table3" (table $t3 1 funcref))
+)