[d8] Cleanup String creation

- Avoid NewStringType::kNormal where possible
- Use Template::Set const char helper
- Use NewStringType::kInternalized where possible

BUG: v8:10155
Change-Id: I4d19e46879c8a574838d2c25c591e510ef16d89f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2061556Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66333}