[low-power] retransmission frame CSL IE handling

[brianljt]

Describe the bug
Retransmission frame with CSL IE included has wrong MIC which causes retransmission failure.

To Reproduce

1. Start OT1.2 router
2. Start OT1.2 child(mode -)
3. Enable CSL on the child
4. Ping from child to the router

Expected behavior
If retransmission happens, retransmitted frame should not change the content of the frame. However, in current implementation, the CSL IE is updated while MIC not updated. This leads to the router rejects the retransmission frames.

IEEE Std 802.15.4 - 6.7.4.3 Retransmission,

When not using TSCH mode and a frame with the Security Enabled field set to one is retransmitted, the
frame shall be retransmitted without changes and without passing through the outgoing frame security
procedure, as defined in 9.2.1.

[brianljt]

This issue is fixed in PR #6275. However, without updating the CSL IE, the retransmission frame will update the router with incorrect CSL phase info. Need to add counter measure to this.

[brianljt]

Example sniffer log, retransmission frame has incorrect MIC as CSL IE is updated.