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/.editorconfig

@@ -0,0 +1,35 @@
+root = false
+[*.cs]
+
+# Default severity for analyzer diagnostics with category 'StyleCop.CSharp.DocumentationRules'
+dotnet_analyzer_diagnostic.category-StyleCop.CSharp.DocumentationRules.severity = none
+
+# CA1707: Identifiers should not contain underscores
+dotnet_diagnostic.CA1707.severity = none
+
+# SA1600: Elements should be documented
+dotnet_diagnostic.SA1600.severity = none
+
+# SA1601: Partial elements should be documented
+dotnet_diagnostic.SA1601.severity = none
+
+# SA1200: Using directives should be placed correctly
+dotnet_diagnostic.SA1200.severity = none
+
+# CS1591: Missing XML comment for publicly visible type or member
+dotnet_diagnostic.CS1591.severity = none
+
+# SA1210: Using directives should be ordered alphabetically by namespace
+dotnet_diagnostic.SA1210.severity = none
+
+# CA1034: Nested types should not be visible
+dotnet_diagnostic.CA1034.severity = none
+
+# CA2000: Dispose objects before losing scope
+dotnet_diagnostic.CA2000.severity = none
+
+# SA1118: Parameter should not span multiple lines
+dotnet_diagnostic.SA1118.severity = none
+
+# CA1031: Do not catch general exception types
+dotnet_diagnostic.CA1031.severity = none