feat: Add Eliot log tree visualization

[v1gnesh]

Add Eliot Log Support

Hey @willmcgugan,

Firstly, thank you for creating excellent tools for the python ecosystem.
You make working in terminals fun.

In this PR, there is support for viewing Eliot logs with a tree-based visualization while preserving all existing log viewing functionality.

eliot - https://github.com/itamarst/eliot
eliottree - https://github.com/jonathanj/eliottree

Your acceptance of this work will make it even easier for pythonistas to adopt eliot, which I've found is way more useful w.r.t getting to root cause than using print or logger.debug lines :)
It's especially useful for understanding complex application execution flow (asyncio programs for example).

Changes

• Added EliotLogFormat for parsing Eliot logs
• Added tree-based visualization for Eliot logs
• Preserved all existing log viewing capabilities
• Improved UI handling for different log types

Testing

• Tested with both Eliot and non-Eliot logs searchspring.json
• Confirmed proper tree visualization for Eliot logs
• Verified panel layout and key bindings match baseline behavior
• test_eliot.log is generated by python test_eliot.py
• test_eliot-tree.txt is generated by eliot-tree test_eliot.log
• test_eliottree.log is the sample given at https://github.com/jonathanj/eliottree?tab=readme-ov-file#eliottree