Snowddl

- Try to fix markdown formatting on PyPi.
- Enable converter for object type `VIEW` (currently not documented, work in progress).

- Prevent `USER_ROLE` resolver from dropping grants other than `ROLE` grants. User roles may accumulate random grants during normal operation from temporary tables, temporary stages, manually created objects in schemas not managed by SnowDDL.
- Change testing Snowflake account once again.

- Implement missing `comment` parameter for `USER` object type.
- Add more tests.

- Added new supported data type `GEOMETRY` (in addition to existing `GEOGRAPHY`).
- Added env variable `SNOWFLAKE_ENV_PREFIX` to specify `--env-prefix` without explicitly mentioning it in CLI command.
- Added a workaround for Snowflake bug, which creates a grant for hidden MATERIALIZED VIEW when search optimization is enabled for a table.
- Completely reworked an approach to tests. Now tests are executed in 3 steps, each step consists of "snowddl apply" followed by pytest execution. Now it should be much easier to add and maintain a large number of test.

- Expose internal query builder `SnowDDLQueryBuilder` as public class. Now it can be used in external projects.
- Minor internal changes in SQL formatter.

- Implemented proper ALTER for `FILE_FORMAT`, fixed a bug when SnowDDL tried to re-create `FILE_FORMAT` which already exists. Also, `EXTERNAL_TABLE` will not lose association with `FILE_FORMAT` after ALTER.
- Object types `EXTERNAL_FUNCTION`, `EXTERNAL_TABLE`, `FUNCTION`, `PROCEDURE` are now correctly resolved as REPLACE instead of ALTER, when object was actually replaced by `CREATE OR REPLACE ...` command.