Add tooling for powerful search of WhisperBack reports

Closes #20666 (closed)

Examples:

Shows emails of the reporters in the last month:

notmuch search --output=files date:1M.. to:support@tails.net  | ./bin/whisperback-search --output=eval --output-eval='m.reporter' 'm.reporter'

Filters for what we need for #20663 (closed) :

notmuch search --output=files date:2M..  subject:'Bug Report' | ./bin/whisperback-search 'm.reporter and not m.fat_resized and m.fsuuid and "GPT table is corrupt" in m.parts.boot_log'