Use basename to verify collection is named as expected

The problem was that some characters were being uri encoded on one side of the comparison but not the other

Using basename on both side of the comparison should cause both strings to undergo the same transformation

As long as both results are the same, then the validation passed

server/src/model/book.ts

@@ -161,7 +161,7 @@ export class BookNode extends Fileish {
       {
         message: BookValidationKind.INVALID_BOOK_NAME,
         nodesToLoad: I.Set(),
-        fn: () => this.absPath.endsWith(`${this.slug}.collection.xml`)
+        fn: () => this.pathHelper.basename(this.absPath) === this.pathHelper.basename(`${this.slug}.collection.xml`)
           ? I.Set()
           : I.Set([NOWHERE])
       }