Bug: Fix allocations in byte_len_cmp when node is object or array

[HeadHunter483]

Currently there are two cases for byte_len_cmp:

• node is not object or array - just getting length of node value as string
• node is object or array - encoding whole node to slice of bytes and get length of encoded slice

The latter case causes allocations on every call of byte_len_cmp operation. This can lead to OOM errors because garbage collector doesn't clear these slices so often.

Replacing encoding with counting length of object or array node recursively can help significantly reduce allocations and even remove them in certain cases.