onnxruntime

[C#] Add ML Sequences and Maps Create and Process APIs (#16648)

### Description
1) Added Sequence And Maps convenience APIs to create input Sequences
and Maps
and also visit the outputs.

2) Address OrtValue design issue when the values are created on top of
the
managed memory and the ortValues are used for sequence and maps
creation.
We should retain the original managed instances that keep the memory
pinned.
We opt to keep track of those and dispose of them within an instance of
OrtValue
that represents a Map or a Sequence.

3) Set `LangVersion` to default per [MS Versioning
Docs.](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/configure-language-version)

### Motivation and Context
1) When writing code examples, use of Map and Sequences API proved to be
cumbersome.
2) It is a BUG, that we should address, as the managed memory can move
by the GC and lead to
intermittent crashes.
3) Make use of the most feature of the C#.