Refactor push_value_ref() method in MutableVector trait

[evenyag]

Now using MutableVector::push_value_ref is verbose as callers always need to handle the returned Result.

greptimedb/src/datatypes/src/vectors.rs

Line 178 in be897ef

fn push_value_ref(&mut self, value: ValueRef) -> Result<()>;

Most times, callers ensure that the pushed value ref has a valid data type. But they still need to add a safety note in the comment and unwrap the result manually.

greptimedb/src/datatypes/src/schema/column_schema.rs

Lines 148 to 149 in be897ef

	// Safety: Both the vector and default value are created by the data type.
	mutable_vector.push_value_ref(value_ref).unwrap();

Consider refactoring the MutableVector and changing the push_value_ref() to panic by default (with panic section in doc comments). We could rename the old push_value_ref() method to try_push_value_ref().

trait MutableVector {
    fn try_push_value_ref(&mut self, value: ValueRef) -> Result<()>; 

    fn push_value_ref(&mut self, value: ValueRef) -> Result<()> {
        self.try_push_value_ref(value).unwrap()
    }

    fn push_null(&mut self);
}

We could also add a push_null method to make pushing null more convenient

greptimedb/src/common/grpc-expr/src/insert.rs

Lines 99 to 101 in be897ef

	vector
	.push_value_ref(ValueRef::Null)
	.context(CreateVectorSnafu)?;

[etolbakov]

@evenyag I would like to give it a try if you don't mind.