Part of #6736

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

We implemented cast_to_variant for some primitive types in

• implement cast_to_variant kernel to cast native types to VariantArray #8044

Now we need to complete out type support for other Arrow types.

Describe the solution you'd like

Add support for the types named in the title as well.

Describe alternatives you've considered

1. Add the corresponding match arms in the cast_to_variant kernel:
   

   arrow-rs/parquet-variant-compute/src/cast_to_variant.rs

   Line 70 in c25c5a7

   match input_type {

2. add tests (e.g.

   arrow-rs/parquet-variant-compute/src/cast_to_variant.rs

   Lines 125 to 142 in c25c5a7

   	fn test_cast_to_variant_int8() {
   	run_test(
   	Arc::new(Int8Array::from(vec![
   	Some(i8::MIN),
   	None,
   	Some(-1),
   	Some(1),
   	Some(i8::MAX),
   	])),
   	vec![
   	Some(Variant::Int8(i8::MIN)),
   	None,
   	Some(Variant::Int8(-1)),
   	Some(Variant::Int8(1)),
   	Some(Variant::Int8(i8::MAX)),
   	],
   	)
   	}

   )