Add a public profile API for external integrations

[Nnoggie]

Summary

• add a small public Grid2ProfileAPI for external consumers that need profile export/import access
• expose the minimal Grid2 profile helpers needed for exporting a specific profile, decoding profile strings, and importing into an explicit profile key
• keep the old Grid2 import/export flow intact while avoiding external integrations hooking directly into locals/internal implementation details

Context

This is used by the WagoUI project from Method:
https://github.com/methodgg/wago-creator-ui

The previous WagoUI-side implementation had to hook into Grid2 internals to support profile export/import. This change gives external consumers a much cleaner integration point and keeps the addon-owned behavior inside Grid2.

Notes

• export supports explicit profile keys instead of only the currently active profile
• import supports importing into an explicit target profile key
• importing into the currently active profile now properly overwrites it instead of no-oping through AceDB's same-profile guard

[michaelnpsp]

Just a question, the Grid2Options addon is not loaded by default, but the API added is assuming the options addon is loaded, is this correct ? Or should i add a check to load Grid2Options addon to avoid crashes in the API ?

[Nnoggie]

We are handling this on WagoUI side for now by loading the AddOn on demand when needed. I'm not sure if a separate solution is needed, I personally think the current solution is fine.