GUI: load saved decks in limited tournament builders.

The limited deck builder allows to save decks, it would be nice to have a load function to go back to a previously saved deck configuration.
That mostly would be useful for sealed to try multiple builds at first, saving each one, and loading one back before submitting, but also it can happen to swap colors during sideboarding and the time limit makes it harder to change half or all of the deck.
Draft could also benefit slightly from it, although due to the nature of the format this is less needed. Same for sideboarding in constructed, you could have saved "sideboard plans" against meta decks.

I would expect a load during limited tournament builds to not actually load, but:
1. Move all cards from the pool maindeck to sideboard.
2. Remove any basic land from the pool, or they would accumulate.
3. For every non-basic-land card in the loaded deck's maindeck, if that card does exist in the pool (and in right quantity), move it from sideboard to maindeck of the builder.
4. For every basic land in the loaded deck's maindeck, add that land to the pool (preserving the right version)

If there is a card in the loaded deck but not in the builder's pool, maybe alert, but still attempt to do the other changes?

Start by tracing the GUI limited deck builder's existing save flow and how pool, maindeck, sideboard, and basic lands are represented. Add a load action that applies the stated card-moving rules, preserves basic-land versions, and handles unavailable cards; verify the behavior for sealed, draft, and sideboarding scenarios.

Written by the indexing model from the issue text.