[FAB-3654] Remove ledger/util/filterbitarray.go

To create/configure transaction filter metadata in
a block, ledger/util/txvalidationflags.go is used instead of
ledger/util/filterbitarray.go. As filterbitarray.go
is no longer used by any module, we remove the file in this CR.

Change-Id: I9e517f3503a84d14774a752c638797fa292ca053
Signed-off-by: senthil <[email protected]>

Author: cendhu