Fix range_end calculation

[venu]

Issue

We are adding +1 to the last byte excluding /, because of this, we are not receiving events. Escpecially when you set the persmission based on the path like below.

role permission

etcdctl role grant-permission clientx --prefix=true readwrite app_data/clients/clientx2/

watch prefix for app_data/clients/clientx2/ becomes b'app_data/clients/clientx3/' but it supposed to be b'app_data/clients/clientx30' (As slash is part of the key, we shall add +1 to the slash)

Fix

As per etcd3 spec https://etcd.io/docs/v3.3/learning/api/#:~:text=revision%20was%20committed.-,Key%20ranges,-The%20etcd3%20data

By convention, ranges for a request are denoted by the fields key and range_end. The key field is the first key of the range and should be non-empty. The range_end is the key following the last key of the range. If range_end is not given or empty, the range is defined to contain only the key argument. If range_end is key plus one (e.g., “aa”+1 == “ab”, “a\xff”+1 == “b”), then the range represents all keys prefixed with key. If both key and range_end are ‘\0’, then range represents all keys. If range_end is ‘\0’, the range is all keys greater than or equal to the key argument.

Some implementations

https://github.com/etcd-io/etcd/blob/main/client/v3/op.go#L376
https://github.com/gaopeiliang/aioetcd3/blob/4709a2a412cc81d47a8a262e569b4cd62a7659d4/aioetcd3/utils.py#L14

[stalkerg]

https://github.com/etcd-io/etcd/blob/main/client/v3/op.go#L376 -- it's how etcdctl do it.

[stalkerg]

we don't need this encode here we already do it inside new function. Same for other cases.

[stalkerg]

or new function shouldn't worry about conversion and should consume only bytes

[stalkerg]

LGTM

[stalkerg]

@kyujin-cho please review this PR.

[stalkerg]

@kyujin-cho sorry, but ping.