null and empty strings for DD filters and SPT parameters

[mdobrzanski]

Just like JS SDK is updated also react-slashdb SDK needs to be updated.

Filtering for NULL or empty string has been improved in SlashDB v1.7.0.

Related issues:

• https://vtenterprise.atlassian.net/browse/SDB-1690
• null and empty strings for DD filters and SPT parameters js-slashdb#5