feat(sql-backend): revert stream_node column to json type in table fragment

[yezizp2012]

Is your feature request related to a problem? Please describe.

Changed in #15040 . As mentioned as follows, changing it to binary type is to avoid stack overflow when deserializing it in sea-orm. Tried manually by calling serdo json encode/decode functions that was used by sea-orm, but didn't reproduce it. For better readable and maintainable we'd better identify it and revert to json type.

risingwave/src/meta/model_v2/src/fragment.rs

Lines 37 to 41 in 85f0023

	/// This is a workaround to avoid stack overflow when deserializing the `StreamNode` field from sql
	/// backend if we store it as Json. We'd better fix it before using it in production, because it's less
	/// readable and maintainable.
	#[derive(Clone, PartialEq, Eq, DeriveValueType)]
	pub struct StreamNode(#[sea_orm] Vec<u8>);

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

Additional context

No response