add hierarchical path handling to static role endpoints

[fairclothjm]

This PR adds hierarchical path handling to the following APIs:

• Static roles
• Static role passwords
• Manually rotate static role password

This allows creating a static role name with an arbitrary number of forward slashes. For example,

$ vault write ldap/static-role/org/platform/dev \
    username="user3" \
    rotation_period="5m"

Where org/platform/dev is the role name. Creds can be read and rotated using the same role name and the respective API's. For example,

$ vault read ldap/static-cred/org/secure
Key                    Value
---                    -----
dn                     n/a
last_password          a3sQ6OkmXKt2dtx22kAt36YLkkxLsg4RmhMZCLYCBCbvvv67ILROaOokdCaGPEAE
last_vault_rotation    2024-05-03T16:39:27.174164-05:00
password               ECf7ZoxfDxGuJEYZrzgzTffSIDI4tx5TojBR9wuEGp8bqUXbl4Kr9eAgPjmizcvg
rotation_period        5m
ttl                    4m58s
username               user2

$ vault write -f ldap/rotate-role/org/secure

Most importantly, this allows us to perform LIST operations to query the available roles. For example,

$ vault list ldap/static-role/org/
Keys
----
platform/
secure

$ vault list ldap/static-role/org/platform
Keys
----
dev

[fairclothjm]

@benashz @vinay-gopalan I have addressed the bulk of your comments. Any remaining test improvements I will do once we get past feature freeze.