[Proposal]: Params Collections (VS 17.10, .NET 9)

# Params Collections

* [x] Proposed: https://github.com/dotnet/csharplang/blob/main/proposals/params-collections.md
* [ ] Prototype: Not Started
* [ ] Implementation: Not Started
* [ ] Specification: Not Started

## Summary
[summary]: #summary

In C# 12 language added support for creating instances of collection types beyond just arrays.
See [collection expressions](https://github.com/dotnet/csharplang/blob/main/proposals/csharp-12.0/collection-expressions.md).
This proposal extends `params` support to all such collection types.

This is a placeholder issue for this proposal: https://github.com/dotnet/csharplang/blob/main/proposals/params-collections.md

The proposal subsumes earlier proposals for params spans (#1757) and params IEnumerables (#179).

## Design meetings

* https://github.com/dotnet/csharplang/blob/main/meetings/2023/LDM-2023-11-15.md#params-improvements
* https://github.com/dotnet/csharplang/blob/main/meetings/2024/LDM-2024-01-29.md#params-collections
* https://github.com/dotnet/csharplang/blob/main/meetings/2024/LDM-2024-01-31.md#params-collections-evaluation-orders
* https://github.com/dotnet/csharplang/blob/main/meetings/2024/LDM-2024-02-21.md#params-collections
* https://github.com/dotnet/csharplang/blob/main/meetings/2024/LDM-2024-06-12.md#params-span-breaks
* https://github.com/dotnet/csharplang/blob/main/meetings/2024/LDM-2024-06-17.md#params-span-breaks
* https://github.com/dotnet/csharplang/blob/main/meetings/2024/LDM-2024-09-11.md#better-conversion-from-collection-expression-and-params-collections