Electra lfrfid protocol implementation

[Leptopt1los]

What's new

Electra intercom (Romania) lfrfid protocol implementation
Solves #1500 and https://forum.flipper.net/t/electra-intercom/6368

Verification

• Write to t5577 random em4100
• to blocks 3-4 write 0x7E71AAAA 0xAAAAAAAA
• set maxblck to 4
  OR
• Go to lfrfid -> extra actions -> add manually -> Electra Group Electra
• Fill with random data, but set last 3 bytes as 7E 71 AA
• Save the dump, write to t5577
  OR
• Get original Electra intercom tag
  OR
• Use ask raw dump emulation on another flipper zero

AND read the tag. Must be detected as Electra Group Electra

After this:

• Test reading, writing to t5577 and emulation (read with pm3/another flipper zero)
• Test regression on EM4100 tags

Checklist (For Reviewer)

• PR has description of feature/bug or link to Confluence/Jira task
• Description contains actions to verify feature/bugfix
• I've built this code, uploaded it to the device and verified feature/bugfix

[DrZlo13]

The code works, no regressions, but I don't have the original Electra cards.
It also appears that proxmark does not know this protocol.

Anyway, good job, I think this is a good place to start.

[d3xt3r01]

@skotopes Works. I found a small issue. On latest dev now. After a power off/on the info shows epilogue as 00000000... After an emulation info shows the correct epilogue again.

[skotopes]

@Leptopt1los wanna add fix to this RC? or next one?)

[Leptopt1los]

@skotopes can fix it tomorrow. just need to trigger ‎protocol_electra_encoder_start in render method before printf. or print epilogue directly from decoded data (a faster, but smellier solution)