Issue 3961 - Fix hint box compat: only clear hint box when A3A queue …

[YThibos]

…drains, not every frame

What type of PR is this.

1. Bug
2. Change
3. Enhancement

What have you changed and why?

Information:
Added a gatekeeping boolean on the customHint rendering system to only clear (hintSilent "") when the custom hints queue is empty, leaving room for vanilla hints and mods that use the vanilla system.

Please specify which Issue this PR Resolves.

closes #3961

Please verify the following and ensure all checks are completed.

1. Have you loaded the mission in LAN host?
2. Have you loaded the mission on a dedicated server?

Is further testing or are further changes required?

1. No
2. Yes (Please provide further detail below.)

How can the changes be tested?

Steps:

• Load Antistasi and another mod that uses the vanilla system (I used BuildAndRessources)
• Trigger any action that would display a hint message
  • with BuildAndRessources: also have ACE loaded ZEUS down a BAR Crate, walk up to it and check its resource content
  • could probably also just use a debug command trigger a hint message. Only just thought of that while typing this out...
• If fixed correctly, message displays for full duration instead of glitching in and out of existence

---

Notes: