refactor: avoid unnecessary allocation

[WenyXu]

I hereby agree to the terms of the GreptimeDB CLA.

Refer to a related PR or issue link (optional)

What's changed and what's your intention?

avoid unnecessary allocation

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.30%. Comparing base (0c5f480) to head (551bdaf).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3747      +/-   ##
==========================================
- Coverage   85.65%   85.30%   -0.36%     
==========================================
  Files         944      944              
  Lines      158776   158772       -4     
==========================================
- Hits       135997   135437     -560     
- Misses      22779    23335     +556     

[tisonkun]

When you use Vec<&'a [u8]>, an extra allocation happen at

                                    PutRequest::new()
                                        .with_key(key.into_bytes())
                                        .with_value(value),

where

    pub fn with_value(mut self, value: impl Into<Vec<u8>>) -> Self {
        self.value = value.into();
        self
    }

impl<T: Clone> From<&[T]> for Vec<T> {
    fn from(s: &[T]) -> Vec<T> {
    /// Allocate a `Vec<T>` and fill it by cloning `s`'s items.
        s.to_vec()
    }
}

See also #3740 (comment)

[evenyag]

When you use Vec<&'a [u8]>, an extra allocation happen at

                                    PutRequest::new()
                                        .with_key(key.into_bytes())
                                        .with_value(value),

where

    pub fn with_value(mut self, value: impl Into<Vec<u8>>) -> Self {
        self.value = value.into();
        self
    }

impl<T: Clone> From<&[T]> for Vec<T> {
    fn from(s: &[T]) -> Vec<T> {
    /// Allocate a `Vec<T>` and fill it by cloning `s`'s items.
        s.to_vec()
    }
}

See also #3740 (comment)

Got it. I'm going to close this @WenyXu

[tisonkun]

But actually IntoChunks and collect makes new vecs also. So it won't be quite differnt.