Add new logging qualifiers to system:completed_requests

Add new logging qualifiers:

statement  Log requests where the like search pattern is found in the query text.

plan Log requests where the plan field value(s) is(are) found in the query plan.

to https://docs.couchbase.com/server/current/manage/monitor/monitoring-n1ql-query.html#sys-completed-req

And to https://docs.couchbase.com/server/current/n1ql/n1ql-rest-api/admin.html#_logging_parameters add:

statement (optional) string

A LIKE search pattern to match against the query text.  All requests where the pattern is found are logged.

plan (optional) JSON

JSON field:value pairs to be matched in the query text.  Multiple field:value pairs can be specified and then all have to be matched (AND).  Values are JSON values as presented in the query plan, e.g. "text" for a string value, 1 for a numeric or [1,2] for an array etc.  Field:value pairs should be unique, but fields may be duplicated, e.g. {"index":"ix1"},{"index","ix2"}  specifies there should be an "index" field in the plan with the value "ix1" AND another "index" field with the value "ix2".