Core: apply suggestions from code review

Applied some code style suggestions by @xperiandri.

Co-authored-by: Andrii Chebukin <XperiAndri@Outlook.com>

Author: webwarrior-ws

src/FSharpLint.Core/Rules/Conventions/Binding/TupleOfWildcards.fs

@@ -17,9 +17,9 @@ let private checkTupleOfWildcards fileContents pattern identifier identifierRang
         let constructorName = identifier |> String.concat "."
         let arguments = Array.create numberOfWildcards "_" |> String.concat ", "
         if numberOfWildcards = 1 then
-            sprintf "%s _" constructorName
+            $"%s{constructorName} _"
         else
-            sprintf "%s(%s)" constructorName arguments
+            $"%s{constructorName}(%s{arguments})"
 
     match pattern with
     | SynPat.Tuple(_isStruct, patterns, _, range) when List.length patterns > 1 && patterns |> List.forall isWildcard ->

src/FSharpLint.Core/Rules/Conventions/FunctionReimplementation/CanBeReplacedWithComposition.fs

@@ -25,14 +25,14 @@ let private validateLambdaCannotBeReplacedWithComposition fileContents _ lambda
                 | (ExpressionUtilities.Identifier(idents, _))::appliedValues
                         when appliedValuesAreConstants appliedValues ->
 
-                    let funcName = String.Join(".", idents)
+                    let funcName = String.Join('.', idents)
                     let funcStringParts = 
                         Seq.append
                             (Seq.singleton funcName)
                             (appliedValues 
                                 |> Seq.take (appliedValues.Length - 1) 
                                 |> Seq.choose (fun value -> ExpressionUtilities.tryFindTextOfRange value.Range fileContents))
-                    let funcString = String.Join(" ", funcStringParts)
+                    let funcString = String.Join(' ', funcStringParts)
 
                     match getLastElement appliedValues with
                     | SynExpr.Ident(lastArgument) when calledFunctionIdents.Length > 1 ->