Further shorten the length of PAT

[JohnNiang]

Prerequisites

• I have searched for related issues in the Issues list.
• This is a feature related to Halo. If it is not an issue with the project itself, it is recommended to submit it in the Discussions.
• If it is a feature suggestion for plugins and themes, please submit it in the respective plugin and theme repositories.

Your current Halo version

2.20.18

Describe this feature

Previously, I requested to keep the length of PAT stable in #5366, but the length is still too long.

So, I request to further shorten the length of PAT. e.g.: pat_cGF0X25hbWU6c2VjcmV0.

❯ echo -n "pat_name:secret" | base64
cGF0X25hbWU6c2VjcmV0

If we didn't like \+, Base62 encoder could be considered.

Additional information

No response