[TS] Fix relative paths for exports (#8517)

Fixes an issue where exports were using incorrect relative paths for
>=3 namespace levels. This is fixed by making the starting range of the
namespace components relative to the amount of components.

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

tests/ts/com/company/test.ts

@@ -0,0 +1,5 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-explicit-any, @typescript-eslint/no-non-null-assertion */
+
+export { Person } from './test/person.js';

tests/ts/com/company/test/person.ts

@@ -0,0 +1,70 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+/* eslint-disable @typescript-eslint/no-unused-vars, @typescript-eslint/no-explicit-any, @typescript-eslint/no-non-null-assertion */
+
+import * as flatbuffers from 'flatbuffers';
+
+
+
+export class Person {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):Person {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsPerson(bb:flatbuffers.ByteBuffer, obj?:Person):Person {
+  return (obj || new Person()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsPerson(bb:flatbuffers.ByteBuffer, obj?:Person):Person {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new Person()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+name():string|null
+name(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+name(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 4);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+age():number {
+  const offset = this.bb!.__offset(this.bb_pos, 6);
+  return offset ? this.bb!.readInt16(this.bb_pos + offset) : 0;
+}
+
+static startPerson(builder:flatbuffers.Builder) {
+  builder.startObject(2);
+}
+
+static addName(builder:flatbuffers.Builder, nameOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, nameOffset, 0);
+}
+
+static addAge(builder:flatbuffers.Builder, age:number) {
+  builder.addFieldInt16(1, age, 0);
+}
+
+static endPerson(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static finishPersonBuffer(builder:flatbuffers.Builder, offset:flatbuffers.Offset) {
+  builder.finish(offset);
+}
+
+static finishSizePrefixedPersonBuffer(builder:flatbuffers.Builder, offset:flatbuffers.Offset) {
+  builder.finish(offset, undefined, true);
+}
+
+static createPerson(builder:flatbuffers.Builder, nameOffset:flatbuffers.Offset, age:number):flatbuffers.Offset {
+  Person.startPerson(builder);
+  Person.addName(builder, nameOffset);
+  Person.addAge(builder, age);
+  return Person.endPerson(builder);
+}
+}