Add config for default bucket space merge inhibition during global merges
Not wired to anything yet, but allows for feature flag to be created.
@@ -293,3 +293,9 @@ implicitly_clear_bucket_priority_on_schedule bool default=true
## involved in a given merge have previously reported (as part of bucket info fetching)
## that they support the unordered merge feature.
use_unordered_merge_chaining bool default=true
+
+## If true, inhibits _all_ merges to buckets in the default bucket space if the current
+## cluster state bundle indicates that global merges are pending in the cluster, i.e.
+## one or more nodes is in maintenance mode in the default bucket space but marked up in
+## the global bucket space.
+inhibit_default_merges_when_global_merges_pending bool default=false
