…daemons

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#### Description
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HLD: https://github.com/sonic-net/SONiC/blob/master/doc/smart-switch/graceful-shutdown/graceful-shutdown.md
These changes build upon enhancements in [`sonic-platform-daemons#667`](sonic-net#667)

This PR introduces **graceful shutdown and startup orchestration** across SONiC platform daemons to ensure safe DPU and peripheral module transitions during reboot or administrative state changes.

Key updates include:
- Integration of `ModuleBase` lifecycle methods (`module_pre_shutdown`, `module_post_startup`, and `set_admin_state_gracefully`) into platform daemons.
- Move graceful handling of PCIe detach/reattach and sensor reload sequences into set_admin_state_gracefully.
- State tracking in `CHASSIS_MODULE_TABLE` via `STATE_DB` to synchronize transition state across processes.
- File-based operation locks to prevent concurrent access to shared hardware resources.

#### Motivation and Context
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Platform daemons currently perform shutdown and startup independently, leading to:
- Race conditions during DPU detachment.
- Inconsistent Redis state across PMON daemons.
- Uncoordinated sensor and PCIe transitions during reboot.

This change introduces a unified **graceful shutdown framework** for SmartSwitch modules.
It ensures predictable module transitions, preserves hardware health, and supports orchestrated restarts without transient hardware errors.

#### How Has This Been Tested?
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Testing performed on both **DPU-enabled (SmartSwitch)**.

**Functional validation**
- Verified end-to-end reboot flow with DPU detach/reattach sequence.
- PCIe state (`detaching/attaching`) reflected in `STATE_DB`.
- `pcied` daemon logs confirm ordered detach before reboot and reattach after startup.
- Confirmed no stale Redis entries or orphaned locks post-reboot.

**Unit tests executed**

- tests/test_DaemonPcied.py
- tests/test_chassisd_graceful.py

Coverage includes:
- Transition flag handling
- Timeout behavior
- DB write/read operations
- Graceful admin state flow

**Manual validation**

#### Additional Information (Optional)