EffectZone for AlternativeCost also acts as AffectedZone

**Describe the bug**
If a card has an AlternativeCost static ability with an EffectZone parameter, then that parameter not only decides what zones the effect functions in, but also what zones another card can be in to be affected by that ability.

**To Reproduce**
Steps to reproduce the behavior:
1. Begin a Vanguard game with Etched Oracle Avatar
2. Attempt to cast a spell from your hand (or from anywhere other than the command zone)
3. Note that you are not given the option of paying WUBRG, despite Etched Oracle Avatar's AlternativeCost ability

**Expected behavior**
The EffectZone for AlternativeCost static abilities, like other static abilities, should determine only what zones the source can be in for the ability to take effect, rather than the zones that other cards can be in for the ability to affect them.

**Desktop (please complete the following information):**
- OS: Windows 11
- Browser: Firefox
- Version: 2.0.12-SNAPSHOT-03.20

**Additional context**
In the Etched Oracle Avatar example, in a Vanguard+Commander game with Etched Oracle Avatar, the alternate cost will be available for casting ones commander (though the option appears twice in the selection, for some reason). I believe Etched Oracle Avatar is the only card impacted by this bug at present.