feat: added allocs profile type

[gianarb]

allocs is the unique profile type missed.

Signed-off-by: Gianluca Arbezzano gianarb92@gmail.com

[narqo]

I was under the impression, that "allocs" profile is exactly the same data as "heap" profile, but with "alloc_space" set as the default value of sample_index. I.e. go tool pprof -sample_index=alloc_space heap.pb.gz:

The allocs profile is the same as the heap profile but changes the default pprof display to -alloc_space [..]

Refer to https://github.com/golang/go/blob/0915a19a115ba6bd2a5a95178bfaa076041d270b/src/runtime/pprof/pprof.go#L517-L526

Is there any value in supporing it explicetly in collector?

[gianarb]

I think we are probably not using the right name internally, @goller what do you think? Should we change allocs to alloc_space ?! We also have a space that fails and we do not know how to handle, so maybe there is something we are not doing right in our side collections and naming all the profiles!

[narqo]

A thing I've noticed recently, which is convincing me, that allocs is somewhere rudimental: from the supported flags in kubectl:

--profile string
  [..] One of (none|cpu|heap|goroutine|threadcreate|block|mutex)