Add JSON output support to makoctl list and makoctl history

[arebaka]

This pull request adds support for JSON-formatted output via the -j flag for the following commands:

• makoctl list
• makoctl history

When the flag is provided, the output is serialized as JSON, making it easier to consume in scripts and external tools.

Changes:

• Added -j flag parsing to relevant CLI commands
• Implemented recursive serialization of D-Bus sd_bus_message structures into valid JSON
• Supports:
  • Basic types: string, bool, byte, int32, uint32
  • Variants (v)
  • Dictionaries (a{sv}, a{ss})
  • Arrays (a[...])
• Safely escapes strings and handles nested containers

Example usage:

makoctl list -j | jq .
makoctl history -j | jq '.[].summary'

Tested:

• Output is valid JSON (verified with jq)
• Handles all expected fields: summary, app-name, urgency, actions, etc
• Works with nested and complex D-Bus structures

Motivation:

This makes makoctl significantly more script- and automation-friendly, especially for use in status bars, dashboards, or notification diagnostics.

Closes #580
CC: @arebaka

[parisni]

really nice, hope json output could be restored soon on mako

[onion108]

looking forward for this to be merged!

[aphelei]

works well