Adding decoding of multipart identifiers, default schema workaround (#295)

This change adds a couple things

_Multipart Identifier Decoding_
The ability to decode a multipart identifier (with or without escaping) has been added to the SqlScriptFormatter utility class. This code is utilized to split a table name provided to the edit/initialize request into schema and table name.

_Default Schema Workaround_
The code that retrieves the SMO metadata objects originally used the `[]` operator to access the objects. Due to a bug(?) in SMO, this results in problems when loading tables without a default schema (in our case if you're logged in as SA). Using the metadata object constructors gets around this issue, we are explicitly using them.

* Adding decoding of multipart identifiers
Adding code fix for default schema issue

* Adding some more localizable strings for errors when loading metadata

* Adding localization files... again?

* Changes as per pull request comments

src/Microsoft.SqlTools.ServiceLayer/Utility/SqlScriptFormatter.cs

@@ -176,6 +176,83 @@ namespace Microsoft.SqlTools.ServiceLayer.Utility
             return literal;
         }
 
+        public static string[] DecodeMultipartIdenfitier(string multipartIdentifier)
+        {
+            StringBuilder sb = new StringBuilder();
+            List<string> namedParts = new List<string>();
+            bool insideBrackets = false;
+            bool bracketsClosed = false;
+            for (int i = 0; i < multipartIdentifier.Length; i++)
+            {
+                char iChar = multipartIdentifier[i];
+                if (insideBrackets)
+                {
+                    if (iChar == ']')
+                    {
+                        if (HasNextCharacter(multipartIdentifier, ']', i))
+                        {
+                            // This is an escaped ]
+                            sb.Append(iChar);
+                            i++;
+                        }
+                        else
+                        {
+                            // This bracket closes the bracket we were in
+                            insideBrackets = false;
+                            bracketsClosed = true;
+                        }
+                    }
+                    else
+                    {
+                        // This is a standard character
+                        sb.Append(iChar);
+                    }
+                }
+                else
+                {
+                    switch (iChar)
+                    {
+                        case '[':
+                            if (bracketsClosed)
+                            {
+                                throw new FormatException();
+                            }
+
+                            // We're opening a set of brackets
+                            insideBrackets = true;
+                            bracketsClosed = false;
+                            break;
+                        case '.':
+                            if (sb.Length == 0)
+                            {
+                                throw new FormatException();
+                            }
+
+                            // We're splitting the identifier into a new part
+                            namedParts.Add(sb.ToString());
+                            sb = new StringBuilder();
+                            bracketsClosed = false;
+                            break;
+                        default:
+                            if (bracketsClosed)
+                            {
+                                throw new FormatException();
+                            }
+
+                            // This is a standard character
+                            sb.Append(iChar);
+                            break;
+                    }
+                }
+            }
+            if (sb.Length == 0)
+            {
+                throw new FormatException();
+            }
+            namedParts.Add(sb.ToString());
+            return namedParts.ToArray();
+        }
+
         #region Private Helpers
 
         private static string SimpleFormatter(object value)
@@ -260,6 +337,12 @@ namespace Microsoft.SqlTools.ServiceLayer.Utility
             return "0x" + BitConverter.ToString(bytes).Replace("-", string.Empty);
         }
 
+        private static bool HasNextCharacter(string haystack, char needle, int position)
+        {
+            return position + 1 < haystack.Length
+                   && haystack[position + 1] == needle;
+        }
+
         /// <summary>
         /// Returns a valid SQL string packaged in single quotes with single quotes inside escaped
         /// </summary>