Part of #7497, closes#8817.
## Problem
See #8817.
## Summary of changes
**compute_ctl**
- Renew lsn lease as soon as `/configure` updates pageserver_connstr,
use `state_changed` Condvar for synchronization.
**pageserver**
As mentioned in
https://github.com/neondatabase/neon/issues/8817#issuecomment-2315768076,
we still want some permanent error reported if a lease cannot be
granted. By considering attachment mode and the added
`lsn_lease_deadline` when processing lease requests, we can also bound
the case of bad requests to a very short period after migration/restart.
- Refactor https://github.com/neondatabase/neon/pull/9024 and move
`lsn_lease_deadline` to `AttachedTenantConf` so timeline can easily
access it.
- Have separate HTTP `init_lsn_lease` and libpq `renew_lsn_lease` API.
- Always do LSN verification for the initial HTTP lease request.
- LSN verification for the renewal is **still done** when tenants are
not in `AttachedSingle` and we have pass the `lsn_lease_deadline`, which
give plenty of time for compute to renew the lease.
**neon_local**
- add and call `timeline_init_lsn_lease` mgmt_api at static endpoint
start. The initial lsn lease http request is sent when we run `cargo
neon endpoint start <static endpoint>`.
## Testing
- Extend `test_readonly_node_gc` to do pageserver restarts and
migration.
## Future Work
- The control plane should make the initial lease request through HTTP
when creating a static endpoint. This is currently only done in
`neon_local`.
Signed-off-by: Yuchen Liang <yuchen@neon.tech>