Crawler: fix missing generic types on subclasses. (#2760)

## Changes

This PR simply adds in some missing generic annotations for crawler
implementations.

Author: asnare

src/databricks/labs/ucx/hive_metastore/table_size.py

@@ -22,7 +22,7 @@ class TableSize:
     size_in_bytes: int
 
 
-class TableSizeCrawler(CrawlerBase):
+class TableSizeCrawler(CrawlerBase[TableSize]):
     def __init__(self, backend: SqlBackend, schema, include_databases: list[str] | None = None):
         """
         Initializes a TablesSizeCrawler instance.

src/databricks/labs/ucx/hive_metastore/tables.py

@@ -476,7 +476,7 @@ def _describe(self, catalog: str, database: str, table: str) -> Table | None:
             return None
 
 
-class FasterTableScanCrawler(CrawlerBase):
+class FasterTableScanCrawler(CrawlerBase[Table]):
     """
     FasterTableScanCrawler is a specialized version of TablesCrawler that uses spark._jsparkSession to utilize
     faster scanning with Scala APIs.

src/databricks/labs/ucx/hive_metastore/udfs.py

@@ -33,7 +33,7 @@ def key(self) -> str:
         return f"{self.catalog}.{self.database}.{self.name}".lower()
 
 
-class UdfsCrawler(CrawlerBase):
+class UdfsCrawler(CrawlerBase[Udf]):
     def __init__(self, backend: SqlBackend, schema: str, include_databases: list[str] | None = None):
         """
         Initializes a UdfsCrawler instance.