Ghast explosion converts obsidian into crying obsidian

[zenfyrdev]

Discussed in #121

^{Originally posted by Rad586 April 28, 2024}
Tear relates to crying, then ghast tear probably relates to crying obsidian.
When a ghast explodes, it turns obsidians within range into crying obsidians.

This feature expands the way of obtaining crying obsidians, and makes player more aware of the new explosion feature, since it can easily break a nether portal.

Considering the difficulty of obtaining crying obsidians, it's better to set a cap on the conversion, or make it random.