[PLUGIN-1931] Add defaults for Time and Range Partitioning in BQ source plugin

[adrikagupta]

If we pass a filter input in BQ source plugin and keep partitionFromDate and partitionToDate values as empty for a table where requirePartitionFilter is set as true, then the preview/deployment run will fail because since requirePartitionFilter is true, the query requires a mandatory “where” clause on partitioning column.
Different types of partitioning for BQ are listed in https://cloud.google.com/bigquery/docs/partitioned-tables .

To fix we are adding defaults for range, time unit and ingestion partitioning which would be used if requirePartitionFilter is set as true and no partitioning inputs are passed. The default would be "parititioning-column is NOT NULL OR parititioning-column is NULL" to get the entire data.
A few things were noted when considering these defaults:

• Time-unit partitioning columns can have future-dated values.
• We are not using startDate and endDate for range partitioning, as it's possible to have values that do not lie within the specified range.

Also, we have added limit and order by fields in UI since filter field is only meant for WHERE clause.

Testing:

• Created a pipeline with BQ source plugin. Used a table having requirePartitioningFilter as true and ingestion partitioning. Provided filter as "1=1", order by and limit fields. Preview and deployment run was successful.
• Created a pipeline with BQ source plugin. Used a table having requirePartitioningFilter as true and time-unit partitioning. Provided filter as "1=1", order by and limit fields. Preview and deployment run was successful.
• Created a pipeline with BQ source plugin. Used a table having requirePartitioningFilter as true and range partitioning. Provided filter as "1=1", order by and limit fields. Preview and deployment run was successful.

[itsankit-google]

one small comment, otherwise LGTM