Allow specifying a custom Dapr sidecar resource name via DaprSidecarOptions.SidecarName

[Copilot]

The sidecar resource name was always derived as {resourceName}-dapr, making it impossible to align the Aspire dashboard name with the Dapr app-id or any meaningful custom identifier.

Changes

• DaprSidecarOptions – New SidecarName property; when null/whitespace, falls back to the existing {resourceName}-dapr default
• DaprSidecarExportOptions – Added matching SidecarName field and wired it through ToDaprSidecarOptions()
• IDistributedApplicationComponentBuilderExtensions – Extracted private WithDaprSidecarCore helper that accepts an explicit name; the options-based overload reads SidecarName before resource creation; callback-based overload unchanged

Usage

builder.AddProject<MyService>("my-service")
    .WithDaprSidecar(new DaprSidecarOptions
    {
        SidecarName = "my-custom-sidecar",
        AppId = "my-service"
    });