HPCC-11306 Localise legacy ECLWatch pages embeded in new ECLWatch

Those legacy ECLWatch pages include System Servers page, Cluster
Processes page, Target Clusters page, as well as linked pages
from those three pages. Use HTTP Accept-Language header to decide
which language is displayed. Read display strings from a language
resource file. Display the strings on the legacy ECLWatch pages.

Signed-off-by: Kevin Wang kevin.wang@lexisnexis.com