Use correct scopes for OAuth U2M and M2M flows

[kravets-levko]

Fixes databricks/databricks-sql-nodejs#226

This PR also contains some preparation work/refactoring, and is easier to review commit by commit:

• explicitly define which flow to use (04011e451e8bd27844bc811327157acddc09a623). We still rely on presense of clientSecret option, but now this condition is moved all the way up to DBSQLClient. OAuthManager uses dedicated option to choose which flow to use
• when refreshing token, use the same scope as when getting the one (d587eb2a05b1409eb58967441dcc6ae3bb78f5db). U2M and M2M flows refresh token in a different way (M2M actually just obtains a new token). Previously we hard-coded scopes for M2M refresh, but, since Azure and In-House OAuth need different scopes, instead of adding one more hard-code we save token's scopes when obtaining one, and then use the same scope when "refreshing"
• fix Azure scopes for M2M flow (9f1c540b77965d4e30fb213c31c6f434af92a392)

[codecov-commenter]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (3953e5d) 0.00% compared to head (e82d2ed) 90.67%.

Files	Patch %	Lines
...ib/connection/auth/DatabricksOAuth/OAuthManager.ts	96.29%	0 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #228 +/- ## ========================================= + Coverage 0 90.67% +90.67% ========================================= Files 0 62 +62 Lines 0 1458 +1458 Branches 0 250 +250 ========================================= + Hits 0 1322 +1322 - Misses 0 84 +84 - Partials 0 52 +52 ```

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