Fix OPT_INDEX_TAGS not properly delegated

The options object did not do anything in this class. Now it caused
a bug. The raw mode is set to false while the constructor is called
and later changes to true.

This is the easiest way of fixing this. The underlying problem may
need more investigation.

Change-Id: I2fa8c686bd67c983fde75a91b1fa0fa2bbced6c8
Fix missing options bug in GetClaims

The problem is that the raw mode setting is false when the builder
is constructed. Using lazy initialization to create the serialization
options seems to work.

(This also fixes GetClaimsTest, which misfired on snak's datatypes
now correctly being included in the output.)

Change-Id: Ic1c7d5cf9c1442230ef67ba3d3b6359ccb46c5d8