Clone of UnwrapParamsArray fpr params collections

[AlekseyTs]

        [Fact]
        public async Task UnwrapParamsCollection()
        {
            var markup = """
                using System;
                using System.Collections.Generic;

                class C {
                    C(params IEnumerable<Action<int>> a) {
                        new C($$
                    }
                }
                """;
            await VerifyBuilderAsync(markup);
        }

Observed:

Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Completion.CompletionProviders.SuggestionModeCompletionProviderTests.UnwrapParamsCollection [FAIL]
  Expecting a suggestion mode, but none was present
  Expected: True
  Actual:   False
  Stack Trace:
    D:\GitHub\roslyn\src\EditorFeatures\CSharpTest\Completion\CompletionProviders\SuggestionModeCompletionProviderTests.cs(1541,0): at Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Completion.CompletionProviders.SuggestionModeCompletionProviderTests.<CheckResultsAsync>d__88.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
    D:\GitHub\roslyn\src\EditorFeatures\CSharpTest\Completion\CompletionProviders\SuggestionModeCompletionProviderTests.cs(1512,0): at Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Completion.CompletionProviders.SuggestionModeCompletionProviderTests.<VerifyWorkerAsync>d__87.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
    D:\GitHub\roslyn\src\EditorFeatures\CSharpTest\Completion\CompletionProviders\SuggestionModeCompletionProviderTests.cs(1502,0): at Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Completion.CompletionProviders.SuggestionModeCompletionProviderTests.<VerifyBuilderAsync>d__86.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
    D:\GitHub\roslyn\src\EditorFeatures\CSharpTest\Completion\CompletionProviders\SuggestionModeCompletionProviderTests.cs(833,0): at Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Completion.CompletionProviders.SuggestionModeCompletionProviderTests.<UnwrapParamsCollection>d__52.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)