fix(snowflake): generate LIMIT when OFFSET exists #4575

[geooo109]

Fixes snowflake problem #4575

This PR allows the generation of snowflake queries when the OFFSET is present in the input dialect without a LIMIT.

Based on the snowflake's doc, an OFFSET must always match with a LIMIT. Based on the discussion here, a LIMIT NULL can be inserted into the query in order to be parsed correctly.

Example:

>>> sqlglot.transpile("SELECT 1 ORDER BY 1 OFFSET 0", read="trino", write="snowflake")
['SELECT 1 ORDER BY 1 LIMIT NULL OFFSET 0']

Docs
Snowflake LIMIT

[georgesittas]

Curious if this fix is only relevant to Snowflake.