chassis-power: Create initial application

Create the new chassis power monitor application and a service file that
would start it. Make the new application available via a meson option.

Tested: Ver

chassis-power: Create initial application

Create the new chassis power monitor application and a service file that
would start it. Make the new application available via a meson option.

Tested: Verified the service and application start with no errors.
```
root@p10bmc:~# systemctl status phosphor-chassis-power.service
● phosphor-chassis-power.service - Chassis Power Monitor
Loaded: loaded
(/usr/lib/systemd/system/phosphor-chassis-power.service; enabled;
preset: enabled)
Active: active (running) since Mon 2025-11-10 19:08:09 UTC; 4min 28s ago
Invocation: 6f0cac0ee4e04066b68ba448aa2d7ccc
Main PID: 549 (phosphor-chassi)
CPU: 29ms
CGroup: /system.slice/phosphor-chassis-power.service
└─549 /usr/libexec/phosphor-power/phosphor-chassis-power

Nov 10 19:08:09 p10bmc systemd[1]: Started Chassis Power Monitor.

root@p10bmc:~# ps |grep chassis
549 root 14928 S /usr/libexec/phosphor-power/phosphor-chassis-power
```

Change-Id: Ia0ab5bc6c578b8203f09feec9b6927059db0f883
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>

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