8290966: G1: Record number of PLAB filled and number of direct allocations

src/hotspot/share/gc/g1/g1Allocator.cpp

src/hotspot/share/gc/g1/g1Allocator.hpp

src/hotspot/share/gc/g1/g1CollectedHeap.cpp

src/hotspot/share/gc/g1/g1EvacStats.cpp

src/hotspot/share/gc/g1/g1EvacStats.hpp

src/hotspot/share/gc/g1/g1EvacStats.inline.hpp

src/hotspot/share/gc/shared/gcHeapSummary.hpp

src/hotspot/share/jfr/metadata/metadata.xml

test/hotspot/jtreg/gc/g1/plab/lib/LogParser.java