Xcvrd Refactor 4/13: Move CMIS logic in process_single_logical_port into its own function

[bobby-nexthop]

Description

This change moves CMIS processing into a new function process_cmis_state_machine. This will be broken up further in future PRs

Motivation and Context

xcvrd has gotten to 4000 lines long. To make things easier, we'd like to refactor it. This is the second PR in a series that aims to do the following:

Task	PR
1) Move functions used across multiple files in xcvrd to utils/common.py	#654
2) Move CmisManagerTask into cmis/cmis_manager_task.py	#691
3) Split task_worker into process_single_lport	#701
4) Move cmis logic out of process_single_lport	#716
4) Rename xcvrd/xcvrd_utilities to xcvrd/utils	bobby-nexthop#3
5) Add handle_cmis_inserted_state function	bobby-nexthop#4
6) Add handle_cmis_dp_pre_init_check_state function	bobby-nexthop#5
7) Add handle_cmis_dpdeinit_state function	bobby-nexthop#6
8) Add handle_cmis_ap_conf_state function	bobby-nexthop#7
9) Add handle_cmis_dp_init_state	bobby-nexthop#8
10) Add handle_cmis_txon_state	bobby-nexthop#9
11) Add handle_cmis_activate_state	bobby-nexthop#10

The new flow will go from calling task_worker() to

How Has This Been Tested?

1. All unit tests pass
2. tested on device with no issues, links all up.

Additional Information (Optional)

[mssonicbld]

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[bobby-nexthop]

@mihirpat1 @prgeor

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Pull request overview

This PR refactors the CmisManagerTask by extracting CMIS state machine processing logic from process_single_lport into a new dedicated function process_cmis_state_machine. This is part 4 of a larger refactoring effort to improve code organization and maintainability of the xcvrd daemon.

• Extracted state machine logic into process_cmis_state_machine for better code organization
• Refactored process_single_lport to validate inputs and prepare data before invoking the state machine
• Preserved all existing functionality and error handling paths

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[prgeor]

@bobby-nexthop is there any change in the logic or only in code arranagement?