* Make `async:true` the default for `invoke` calls (#3750)
* Switch away from native grpc impl. (#3728)
* Remove usage of the 'deasync' library from @pulumi/pulumi. (#3752)
* Only retry as long as we get unavailable back. Anything else continues. (#3769)
* Handle all errors for now. (#3781)
* Do not assume --yes was present when using pulumi in non-interactive mode (#3793)
* Upgrade all paths for sdk and pkg to v2
* Backport C# invoke classes and other recent gen changes (#4288)
Adjust C# generation
* Replace IDeployment with a sealed class (#4318)
Replace IDeployment with a sealed class
* .NET: default to args subtype rather than Args.Empty (#4320)
* Adding system namespace for Dotnet code gen
This is required for using Obsolute attributes for deprecations
```
Iam/InstanceProfile.cs(142,10): error CS0246: The type or namespace name 'ObsoleteAttribute' could not be found (are you missing a using directive or an assembly reference?) [/Users/stack72/code/go/src/github.com/pulumi/pulumi-aws/sdk/dotnet/Pulumi.Aws.csproj]
Iam/InstanceProfile.cs(142,10): error CS0246: The type or namespace name 'Obsolete' could not be found (are you missing a using directive or an assembly reference?) [/Users/stack72/code/go/src/github.com/pulumi/pulumi-aws/sdk/dotnet/Pulumi.Aws.csproj]
```
* Fix the nullability of config type properties in C# codegen (#4379)
Adds a new resource option `aliases` which can be used to rename a resource. When making a breaking change to the name or type of a resource or component, the old name can be added to the list of `aliases` for a resource to ensure that existing resources will be migrated to the new name instead of being deleted and replaced with the new named resource.
There are two key places this change is implemented.
The first is the step generator in the engine. When computing whether there is an old version of a registered resource, we now take into account the aliases specified on the registered resource. That is, we first look up the resource by its new URN in the old state, and then by any aliases provided (in order). This can allow the resource to be matched as a (potential) update to an existing resource with a different URN.
The second is the core `Resource` constructor in the JavaScript (and soon Python) SDKs. This change ensures that when a parent resource is aliased, that all children implicitly inherit corresponding aliases. It is similar to how many other resource options are "inherited" implicitly from the parent.
Four specific scenarios are explicitly tested as part of this PR:
1. Renaming a resource
2. Adopting a resource into a component (as the owner of both component and consumption codebases)
3. Renaming a component instance (as the owner of the consumption codebase without changes to the component)
4. Changing the type of a component (as the owner of the component codebase without changes to the consumption codebase)
4. Combining (1) and (3) to make both changes to a resource at the same time
