Moved analyzer tests to its own project

Also moves tests to `./test` which makes it possible
for all test projects to share the same .editorconfig
files and similar.

test/Spectre.Console.Analyzer.Tests/Unit/Analyzers/NoPromptsDuringLiveRenderablesTests.cs

@@ -0,0 +1,104 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Testing;
+using Xunit;
+
+namespace Spectre.Console.Analyzer.Tests.Unit.Analyzers
+{
+    public class NoPromptsDuringLiveRenderablesTests
+    {
+        private static readonly DiagnosticResult _expectedDiagnostics = new(
+            Descriptors.S1021_AvoidPromptCallsDuringLiveRenderables.Id,
+            DiagnosticSeverity.Warning);
+
+        [Fact]
+        public async Task Prompt_out_of_progress_does_not_warn()
+        {
+            const string Source = @"
+using Spectre.Console;
+
+class TestClass 
+{
+    void Go()
+    {
+        var s = AnsiConsole.Ask<string>(""How are you?"");
+    }
+}";
+
+            await SpectreAnalyzerVerifier<NoPromptsDuringLiveRenderablesAnalyzer>
+                .VerifyAnalyzerAsync(Source)
+                .ConfigureAwait(false);
+        }
+
+        [Fact]
+        public async Task Instance_variables_warn()
+        {
+            const string Source = @"
+using Spectre.Console;
+
+class TestClass 
+{
+    public IAnsiConsole _console = AnsiConsole.Console;
+
+    public void Go()
+    {
+        _console.Status().Start(""starting"", context =>
+        {
+            var result = _console.Confirm(""we ok?"");
+        });
+    }
+}";
+
+            await SpectreAnalyzerVerifier<NoPromptsDuringLiveRenderablesAnalyzer>
+                .VerifyAnalyzerAsync(Source, _expectedDiagnostics.WithLocation(12, 26))
+                .ConfigureAwait(false);
+        }
+
+        [Fact]
+        public async Task Prompt_in_progress_warns()
+        {
+            const string Source = @"
+using Spectre.Console;
+
+class TestClass 
+{
+    void Go()
+    {
+        AnsiConsole.Progress().Start(_ =>
+        {
+            AnsiConsole.Ask<string>(""How are you?"");
+        });
+    }
+}";
+
+            await SpectreAnalyzerVerifier<NoPromptsDuringLiveRenderablesAnalyzer>
+                .VerifyAnalyzerAsync(Source, _expectedDiagnostics.WithLocation(10, 13))
+                .ConfigureAwait(false);
+        }
+
+        [Fact]
+        public async Task Can_call_other_methods_from_within_renderables()
+        {
+            const string Source = @"
+using Spectre.Console;
+
+class Program
+{
+    static void Main()
+    {
+        AnsiConsole.Status().Start(""here we go"", context =>
+        {
+            var result = Confirm();
+
+        });
+    }
+
+    static string Confirm() => string.Empty;
+}";
+
+            await SpectreAnalyzerVerifier<NoPromptsDuringLiveRenderablesAnalyzer>
+                .VerifyAnalyzerAsync(Source)
+                .ConfigureAwait(false);
+        }
+    }
+}