[9.20] fix: usr: Fix EDNS yaml output

`dig` was producing invalid YAML when displaying some EDNS options. This has been corrected.

Several other improvements have been made to the display of EDNS option data:
- We now use the correct name for the UPDATE-LEASE option, which was previously displayed as "UL", and split it into separate LEASE and LEASE-KEY components in YAML mode.
- Human-readable durations are now displayed as comments in YAML mode so as not to interfere with machine parsing.
- KEY-TAG options are now displayed as an array of integers in YAML mode.
- EDNS COOKIE options are displayed as separate CLIENT and SERVER components, and cookie STATUS is a retrievable variable in YAML mode.

Closes #5014

Backport of MR !9695

Merge branch 'backport-5014-improve-edns-yaml-processing-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!10414