[Go] Provide more detail on table types in GetObjects

[lidavidm]

See point 16 here: #77

The problem is that SHOW TABLES in Snowflake is not very detailed. We'd have to join across several metadata tables, which could get very expensive.

[lidavidm]

CC @Mandukhai-Alimaa, we need to consider if this is even possible

[Mandukhai-Alimaa]

take