Use embedded entry key object in LedgerEntry Page
Minor clean-up as a follow-up to d2e25fac3a1b5301ee8a2d74c74608be4d3f2711 (change for using a lru map for clean index pages)

RB_ID=127387
 Fix loadtest message size limit and add option to output to a file
 - Fix loadtest message size limit and add option to output to a file

RB_ID=127995