FIX improve statistics API

[fgalan]

• versionRequests counter removal (already covered by GET /versions counter)
• "getAll counters" GET /statistics option
• check docu (not sure if some change would be required)

[fgalan]

@fisuda this PR does some small modifications to one .md file. It would be great if you could sync the Japanese translation. Thanks!

(If PR #4254 is still un-merged when you do that, you can do a PR using hardening/improve-statistics-api as base branch or master as base branch. As you prefer)

[mapedraza]

LGTM

[fisuda]

I sent the PR #4257. Thanks.

[fgalan]

I have done some "coverage analysis"

• Get requests from the "routes map"

cat app/contextBroker/orionRestServices.cpp | grep Request | awk -F '{' '{print $2'} | awk -F ',' '{print $1}' | sed 's/\W//g' | sort -u > request_set1.txt

• Get the requests covered by the statistics

cat lib/common/statistics.cpp | grep ' {\w' | awk -F '{' '{print $2'} | awk -F ',' '{print $1}' | sort -u > requets_set2.txt

• Compare both (diff -u requets_set1.txt requets_set2.txt)

--- requets_set1.txt	2022-12-22 10:26:20.575685478 +0100
+++ requets_set2.txt	2022-12-22 10:28:14.706882935 +0100
@@ -25,7 +25,6 @@
 IndividualContextEntityAttribute
 IndividualContextEntityAttributes
 IndividualContextEntityAttributeWithTypeAndId
-InvalidRequest
 LeakRequest
 LogLevelRequest
 LogTraceRequest

Except for InvalidRequest (which is used in the badVerd logic only, thus is not an actual request) they are equal, so I think the statistic logs covers correctly the current requests.