fcl-db: tests: add comment for SQLite why some test for exact numeric (currency) values, which can not be expressed lossless as double, fail.
Add to testCurrencyValues, also value with decimal point which can be expressed lossless as double.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@27668 3ad0048d-3df7-0310-abae-a5850022a9f2
fcl-db: tests: reduce decimal digits of just added new testCurrency value to 2 because PostgreSQL uses for money data type only 2 decimal places.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@27669 3ad0048d-3df7-0310-abae-a5850022a9f2