fix: restore parameters support when sql passed to SnowflakeHook as str

[grassten]

In 2.1.0 the SnowflakeHook/Operator dropped support for parameters when passing SQL as a string. This re-enables parameterization and keeps query splitting functionality using split_statements from Snowflake (the same function used within execute_string) and then parameterizes and executes the individual queries.

closes #16068

[boring-cyborg]

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[uranusjr]

Implementation looks good to me, the tests should be merged with parametrize.

[potiuk]

Nice! Thanks! Looks great. Thanks for parameterizing the tests!

[github-actions]

The PR is likely OK to be merged with just subset of tests for default Python and Database versions without running the full matrix of tests, because it does not modify the core of Airflow. If the committers decide that the full tests matrix is needed, they will add the label 'full tests needed'. Then you should rebase to the latest master or amend the last commit of the PR, and push it with --force-with-lease.

[boring-cyborg]

Awesome work, congrats on your first merged pull request!