General Changes

• Fix a performance regression in GROUP BY and JOIN queries when the length of the keys is between 16 and 31 bytes.
• Add map_concat() function.
• Performance improvements for filters, projections and dictionary encoded data. This optimization is turned off by default. It can be configured via the optimizer.columnar-processing-dictionary config property or the columnar_processing_dictionary session property.
• Improve performance of aggregation queries with large numbers of groups.
• Improve performance for queries that use ARRAY type.
• Fix querying remote views in MySQL and PostgreSQL connectors.