Update ts codegen (#8421)

Makes the return type of `static getFullyQualifiedName()` be a string literal instead of just the string type

Update tests

Co-authored-by: Björn Harrtell <bjornharrtell@users.noreply.github.com>

tests/ts/union_vector/attacker.ts

@@ -40,7 +40,7 @@ mutate_sword_attack_damage(value:number):boolean {
   return true;
 }
 
-static getFullyQualifiedName():string {
+static getFullyQualifiedName(): "Attacker" {
   return 'Attacker';
 }
 

tests/ts/union_vector/book-reader.ts

@@ -24,7 +24,7 @@ mutate_books_read(value:number):boolean {
   return true;
 }
 
-static getFullyQualifiedName():string {
+static getFullyQualifiedName(): "BookReader" {
   return 'BookReader';
 }
 

tests/ts/union_vector/falling-tub.ts

@@ -24,7 +24,7 @@ mutate_weight(value:number):boolean {
   return true;
 }
 
-static getFullyQualifiedName():string {
+static getFullyQualifiedName(): "FallingTub" {
   return 'FallingTub';
 }
 

tests/ts/union_vector/hand-fan.ts

@@ -40,7 +40,7 @@ mutate_length(value:number):boolean {
   return true;
 }
 
-static getFullyQualifiedName():string {
+static getFullyQualifiedName(): "HandFan" {
   return 'HandFan';
 }
 

tests/ts/union_vector/movie.ts

@@ -67,7 +67,7 @@ charactersLength():number {
   return offset ? this.bb!.__vector_len(this.bb_pos + offset) : 0;
 }
 
-static getFullyQualifiedName():string {
+static getFullyQualifiedName(): "Movie" {
   return 'Movie';
 }
 

tests/ts/union_vector/rapunzel.ts

@@ -24,7 +24,7 @@ mutate_hair_length(value:number):boolean {
   return true;
 }
 
-static getFullyQualifiedName():string {
+static getFullyQualifiedName(): "Rapunzel" {
   return 'Rapunzel';
 }