Make use of the github.com/abcum/bump package to efficiently encode and decode from and to byte slices, whilst at the same time using encoder and decoder pools, instead of creating a new buffer for each encoding / decoding process.
All numbers in encoded keys are now encoded into float64, ensuring that decimal numbers are sorted alongside integers.
The maximum number able to be stored as a float64, without losing precision, is now (1<<53 - 1) - the same maximum number possible in javascript.
