mon: PGMap: reuse existing summary functions to output pool stats

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
(cherry picked from commit e3ba8e82ac8cf10f5e478ce704a4430dc5c2b2ed)

Conflicts:

	src/mon/PGMap.cc
	src/mon/PGMap.h
types: pretty_si_t

Similar to si_t, but leaves a space between the numbers and the units.  In
the degenerate case (no M, K, etc. modifier) there's simply a trailing
space.  For example,

  out << pretty_si_t(num) << "objects/sec";

will look pretty.

Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 9b94f90e0031957717afde16bd056322782232cb)
Use 'k' when printing 'kilo'; accept either 'K' or 'k' as input

Fixes: #4612
Signed-off-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit b43bc1a0b0692818d789f9f489b9aba5dd40522f)
mon: PGMap: rework client IO rate calc and output

Create a function so we can use the same format when outputting per-pool
stats

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
(cherry picked from commit 2cd532001949a947bf5565620371eb4b4e930400)

Conflicts:
	src/mon/PGMap.cc
mon: OSDMonitor: add 'osd pool stats' command

Fixes: #6147

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
(cherry picked from commit 5abe5c273ae2197ae0539191f1c64d6a9ee41873)