### What changes were proposed in this pull request?
When a user have multiple options like `path`, `paTH`, and `PATH` for the same key `path`, `option/options` is non-deterministic because `extraOptions` is `HashMap`. This PR aims to use `CaseInsensitiveMap` instead of `HashMap` to fix this bug fundamentally.
### Why are the changes needed?
Like the following, DataFrame's `option/options` have been non-deterministic in terms of case-insensitivity because it stores the options at `extraOptions` which is using `HashMap` class.
```scala
spark.read
.option("paTh", "1")
.option("PATH", "2")
.option("Path", "3")
.option("patH", "4")
.load("5")
...
org.apache.spark.sql.AnalysisException:
Path does not exist: file:/.../1;
```
### Does this PR introduce _any_ user-facing change?
Yes. However, this is a bug fix for the indeterministic cases.
### How was this patch tested?
Pass the Jenkins or GitHub Action with newly added test cases.
Closes#29160 from dongjoon-hyun/SPARK-32364.
Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
cd16a10475