### What changes were proposed in this pull request?
In the PR, I propose to change rebasing of not-existed dates in the hybrid calendar (Julian + Gregorian since 1582-10-15) in the range (1582-10-04, 1582-10-15). Not existed dates from the range are shifted to the first valid date in the hybrid calendar - 1582-10-15. The changes affect only `rebaseGregorianToJulianDays()` because reverse rebasing from the hybrid dates to Proleptic Gregorian dates does not have such problem.
### Why are the changes needed?
Currently, not-existed dates are shifted by standard difference between Julian and Gregorian calendar on 1582-10-04, for example 1582-10-14 -> 1582-10-24. That's contradict to shifting not existed dates in other cases, for example:
```
scala> sql("select date'1990-9-31'").show
+-----------------+
|DATE '1990-10-01'|
+-----------------+
| 1990-10-01|
+-----------------+
```
### Does this PR introduce any user-facing change?
Yes, this impacts on conversion of Spark SQL `DATE` values to external dates based on non-Proleptic Gregorian calendar. For example, while saving the 1582-10-14 date to ORC files, it will be shifted to the next valid date 1582-10-15.
### How was this patch tested?
- Added tests to `RebaseDateTimeSuite` and to `OrcSourceSuite`
- By existing test suites `DateTimeUtilsSuite`, `DateFunctionsSuite`, `DateExpressionsSuite`, `CollectionExpressionsSuite`, `ParquetIOSuite`.
Closes#28225 from MaxGekk/fix-not-exist-dates.
Authored-by: Max Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
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