[ES|QL] Improve `show functions` command with some additional columns

[dej611]

Description

After #99507 the output of show functions became very useful.
While testing with the Kibana code I've noticed a couple more columns that would be nice to have:

• minParams: number - this is useful to describe variadic functions who still require few parameters to be defined
  • Some examples here are concat(...) with minParams: 1, case with minParams: 3 or cidr_match with minParams: 2
• examples: some short example on how to use the function
• aggregation: true/false can be useful to identify where it can be used (stats vs eval/row/where)
• supportsWildcard: true/false for each argument

[elasticsearchmachine]

Pinging @elastic/es-ql (Team:QL)

[elasticsearchmachine]

Pinging @elastic/elasticsearch-esql (:Query Languages/ES|QL)

[elasticsearchmachine]

Pinging @elastic/es-analytics-geo (Team:Analytics)

[bpintea]

Functionality dropped in #113967.