Fix various lib / test / examples typos (#7017)

Fix various lib / test / examples typos (#7017)

* fix: lib/sqlalchemy/sql/lambdas.py

* fix: lib/sqlalchemy/sql/compiler.py

* fix: lib/sqlalchemy/sql/selectable.py

* fix: lib/sqlalchemy/orm/relationships.py

* fix: lib/sqlalchemy/dialects/mssql/base.py

* fix: lib/sql/test_compiler.py

* fix: lib/sqlalchemy/testing/requirements.py

* fix: lib/sqlalchemy/orm/path_registry.py

* fix: lib/sqlalchemy/dialects/postgresql/psycopg2.py

* fix: lib/sqlalchemy/cextension/immutabledict.c

* fix: lib/sqlalchemy/cextension/resultproxy.c

* fix: ./lib/sqlalchemy/dialects/oracle/cx_oracle.py

* fix: examples/versioned_rows/versioned_rows_w_versionid.py

* fix: examples/elementtree/optimized_al.py

* fix: test/orm/test_attribute.py

* fix: test/sql/test_compare.py

* fix: test/sql/test_type_expression.py

* fix: capitalization in test/dialect/mysql/test_compiler.py

* fix: typos in test/dialect/postgresql/test_reflection.py

* fix: typo in tox.ini comment

* fix: typo in /lib/sqlalchemy/orm/decl_api.py

* fix: typo in test/orm/test_update_delete.py

* fix: self-induced typo

* fix: typo in test/orm/test_query.py

* fix: typos in test/dialect/mssql/test_types.py

* fix: typo in test/sql/test_types.py