Commander precons should be stored in commanderprecons dir, not precons.

**Is your feature request related to a problem? Please describe.**
Some commander decks are stored in precons/ directory, which makes them visible even when playing non-commander game (like Vintage or Legacy).

**Describe the solution you'd like**
Move commander decks to commanderprecons directory.

**Describe alternatives you've considered**
In GUI, hide decks containing commander section when Commander tick box is not selected on the top (in main window, where players and decks are selected)

**Additional context**
Entries with "wrong directory" could be moved right away. Entries with "duplicated" require minor changes.
```
forge/forge-gui/res/quest/precons for i in *; do if ! grep -q 'commander' "$i"; then continue; fi; if [[ -f "../commanderprecons/$i" ]]; then echo "Duplicated: $i"; else echo "Wrong directory: $i"; fi; done | sort
Duplicated: Built from Scratch.dck
Duplicated: Counterpunch.dck
Duplicated: Devour for Power.dck
Duplicated: Eternal Bargain.dck
Duplicated: Evasive Maneuvers.dck
Duplicated: Forged in Stone.dck
Duplicated: Guided by Nature.dck
Duplicated: Heavenly Inferno.dck
Duplicated: Mind Seize.dck
Duplicated: Mirror Mastery.dck
Duplicated: Nature of the Beast.dck
Duplicated: Peer Through Time.dck
Duplicated: Political Puppets.dck
Duplicated: Power Hungry.dck
Duplicated: Sworn to Darkness.dck
Wrong directory: Arcane Maelstrom.dck
Wrong directory: Arm for Battle.dck
Wrong directory: Aura of Courage.dck
Wrong directory: Buckle Up.dck
Wrong directory: Coven Counters.dck
Wrong directory: Draconic Rage.dck
Wrong directory: Dungeons of Death.dck
Wrong directory: Elven Empire.dck
Wrong directory: Enhanced Evolution.dck
Wrong directory: Faceless Menace.dck
Wrong directory: Heads I Win, Tails You Lose.dck
Wrong directory: Land's Wrath.dck
Wrong directory: Lorehold Legacies.dck
Wrong directory: Merciless Rage.dck
Wrong directory: Mystic Intellect.dck
Wrong directory: Phantom Premonition.dck
Wrong directory: Planar Portal.dck
Wrong directory: Primal Genesis.dck
Wrong directory: Prismari Performance.dck
Wrong directory: Quantum Quandrix.dck
Wrong directory: Reap the Tide.dck
Wrong directory: Ruthless Regiment.dck
Wrong directory: Silverquill Statement.dck
Wrong directory: Sneak Attack.dck
Wrong directory: Spirit Squadron.dck
Wrong directory: Symbiotic Swarm.dck
Wrong directory: Timeless Wisdom.dck
Wrong directory: Undead Unleashed.dck
Wrong directory: Upgrades Unleashed.dck
Wrong directory: Vampiric Bloodline.dck
Wrong directory: Witherbloom Witchcraft.dck
```

Example of minor changes:
```
forge/forge-gui/res/quest/precons diff Sworn\ to\ Darkness.dck ../commanderprecons/Sworn\ to\ Darkness.dck
3,13c3,5
< [shop]
< WinsToUnlock=0
< Credits=5000
< MinDifficulty=0
< MaxDifficulty=5
< Description=Ob Nixilis of the Black Oath is a ruthless tyrant who will stop at nothing to achieve his aims. This planeswalker commander saps his oppenents strength, summons powerful demons to the battlefield, and compels the dead to rise and fight again.
< Set=C14
< Image=sworn_to_darkness.png
< [commander]
< 1 Ob Nixilis of the Black Oath+|C14
< [main]
---
> [Commander]
> 1 Ob Nixilis of the Black Oath|C14
> [Main]
71c63,66
< 32 Swamp|C14
---
> 8 Swamp|C14|1
> 8 Swamp|C14|2
> 8 Swamp|C14|3
> 8 Swamp|C14|4
81a77,78
> [Sideboard]
>
```