DuckDB: 0.3.0 Preview Release "Gracilis"

This preview release of DuckDB is named "Gracilis" after the [Grey Teal](https://en.wikipedia.org/wiki/Grey_teal) Binary builds are listed below. Feedback is very welcome. Note: Again, this release introduces a backwards-incompatible change to the on-disk storage format. We suggest you use the EXPORT DATABASE command with the old version followed by IMPORT DATABASE with the new version to migrate your data. See the [documentation](https://duckdb.org/docs/sql/statements/export) for details. This release contains a novel join method, the #1959: Perfect Hash Join. Otherwise there are many improvements and bug fixes however, a list is below: - #2377: Fix current_schema() and current_schemas() - #2371: Installing pandoc so R pkg can be fully checked - #2369: More CI fixes - #2361: ODBC: First version Winsetup - #2360: Issue #2348: Support bankers rounding as default function - #2359: Implement UUID data type - #2358: Fixes minor flag comment - #2357: Issue #2351: Ordered aggregate transformation - #2356: Issue #2286: Numeric SUMMARIZE stats - #2353: Get rid of a couple of Clang warnings. - #2346: Avoid re-using RE2 regex between threads, since RE2 regex objects have locks internally - #2328: CI Fixes - #2321: Issue #1998: Exact Timestamp Subtraction - #2320: Change SET's default scope from GLOBAL to (PG-compatible) SESSION. - #2319: Fix #2315: correctly detect that index joins cannot be used for multi-column indexes, and clean up TPC-DS extension - #2318: Remove extra semicolon. - #2317: Support SET SCHEMA and SET SEARCH_PATH - #2316: Fix for #2304 - #2314: Fix #2313: No Out of Range Error in Index Benchmark - #2311: Issue #2310: Create Index Benchmark - #2306: Windows (64 bits) and -DDISABLE_UNITY=1 - #2302: Fix #2301: ART Leaf Node shrink - #2300: Fix #2293: Correctly escape all special characters (quotes, newlines, tabs, etc) in JSON output of query profiler - #2299: Fix #2296: Avoid requesting O_RDWR permissions when we only need O_WRONLY so we can write to FIFO streams - #2298: Fix #2294: In CSV reader correctly generate column names with many columns - #2297: Issue #2241: Transacted Index Reinsert - #2290: Fix #2289: align default continue prompt - #2287: ODBC: list catalog, schema and test_blob - #2284: Make S3 credentials session scoped - #2282: Fix for bug #2281 - #2280: Initial support to read lists from R client - #2279: Fix #2277: add support for lists of structs to LIST_EXTRACT - #2276: Add support for EXCLUDE and REPLACE clauses - #2275: Run only CRAN tests for valgrind - #2274: Fix #2267: For structs, get the required amount of rows from a non-list child if there is one - #2272: Rename force_parallelism to verify_parallelism - #2271: Make regression run parallel with 2 Threads - #2266: A refactoring around FileSystem - #2265: Allow optional extensions when building the R package - #2263: Regression Test: TPC-DS/H20AI and other adjustments - #2262: Fix #2261: add support for filters pushed down into decimal columns in Parquet files - #2259: Fix a TSAN error for test/sql/window/test_partition_flushing.test - #2255: Make sorting even faster - #2254: More descriptive out-of-memory error when db is launched in-memory - #2253: Regression Tests - #2251: Changes from CRAN 0.2.9 release - #2234: Add support for S3 session token (STS) - #2228: Date functions on Windows