feat: general improvements and minor bugs

Author: ReneSchwarzer

src/WebExpress.WebIndex.Test/WQL/UnitTestWqlWordSearchA.cs

@@ -223,6 +223,7 @@ public void AbstracrSyntaxTree()
         [Theory]
         [InlineData("", true, 0, WqlExpressionType.None, WqlExpressionType.Attribute)]
         [InlineData("text", false, 1, WqlExpressionType.Attribute, WqlExpressionType.Operator)]
+        [InlineData("text ", false, 1, WqlExpressionType.Attribute, WqlExpressionType.Operator)]
         [InlineData("text #", false, 2, WqlExpressionType.Operator, WqlExpressionType.Operator)]
         [InlineData("text ~", false, 2, WqlExpressionType.Operator, WqlExpressionType.Parameter)]
         [InlineData("text ~ (", false, 2, WqlExpressionType.Operator, WqlExpressionType.Parameter)]

src/WebExpress.WebIndex/Wql/IWqlLookaheadToken.cs

@@ -16,7 +16,7 @@ public interface IWqlLookaheadToken
         /// <summary>
         /// Returns the type of the WQL expression represented by this instance.
         /// </summary>
-        WqlExpressionType ExpreesionType { get; }
+        WqlExpressionType ExpressionType { get; }
 
         /// <summary>
         /// Returns the set of tokens that would be syntactically valid at the

src/WebExpress.WebIndex/Wql/WqlLookahead.cs

@@ -25,7 +25,7 @@ public class WqlLookahead : IWqlLookahead
         /// Returns the type of the last token of the WQL expression.
         /// </summary>
         public WqlExpressionType LastExpressionType =>
-            Items.LastOrDefault()?.ExpreesionType ?? WqlExpressionType.None;
+            Items.LastOrDefault()?.ExpressionType ?? WqlExpressionType.None;
 
         /// <summary>
         /// Returns the set of tokens that would be syntactically valid at the

src/WebExpress.WebIndex/Wql/WqlLookaheadToken.cs

@@ -16,7 +16,7 @@ public sealed class WqlLookaheadToken : IWqlLookaheadToken
         /// <summary>
         /// Returns the type of the WQL expression represented by this instance.
         /// </summary>
-        public WqlExpressionType ExpreesionType { get; }
+        public WqlExpressionType ExpressionType { get; }
 
         /// <summary>
         /// Returns the set of tokens that would be syntactically valid at the
@@ -37,13 +37,13 @@ public sealed class WqlLookaheadToken : IWqlLookaheadToken
         /// The WqlToken to associate with this lookahead token. This parameter cannot 
         /// be null.
         /// </param>
-        /// <param name="expreesionType">
+        /// <param name="expressionType">
         /// The type of expression represented by the token.
         /// </param>
-        public WqlLookaheadToken(IWqlToken token, WqlExpressionType expreesionType)
+        public WqlLookaheadToken(IWqlToken token, WqlExpressionType expressionType)
         {
             Token = token;
-            ExpreesionType = expreesionType;
+            ExpressionType = expressionType;
         }
 
         /// <summary>