[SPARK-44407][BUILD][TESTS] Clean up the compilation warnings related to it will become a keyword in Scala 3 and prohibit use these keywords as variable name

[LuciferYang]

What changes were proposed in this pull request?

This pr clean up the compilation warnings related to it will become a keyword in Scala 3, additionally, to facilitate future Scala version migration, a new compiler option has been added to prohibit the use of these keywords as variable names.

Why are the changes needed?

There are some literals, such as enum, given, export, etc., using them as variable names in Scala 2.13 will trigger compilation warnings, but this will become a compilation error in Scala 3.

Scala 2.13

Welcome to Scala 2.13.12 (OpenJDK 64-Bit Server VM, Java 17.0.8).
Type in expressions for evaluation. Or try :help.


scala> val enum: Int = 1
           ^
       warning: Wrap `enum` in backticks to use it as an identifier, it will become a keyword in Scala 3. [quickfixable]
val enum: Int = 1


scala> val export: Int = 1
           ^
       warning: Wrap `export` in backticks to use it as an identifier, it will become a keyword in Scala 3. [quickfixable]
val export: Int = 1


scala> val given: Int = 1
           ^
       warning: Wrap `given` in backticks to use it as an identifier, it will become a keyword in Scala 3. [quickfixable]
val given: Int = 1 

Scala 3

Welcome to Scala 3.3.1 (17.0.8, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.
                                                                                                                                                                                                                                                     
scala> val enum: Int = 1
-- [E032] Syntax Error: --------------------------------------------------------
1 |val enum: Int = 1
  |    ^^^^
  |    pattern expected
  |
  | longer explanation available when compiling with `-explain`
                                                                                                                                                                                                                                                     
scala> val export: Int = 1
-- [E032] Syntax Error: --------------------------------------------------------
1 |val export: Int = 1
  |    ^^^^^^
  |    pattern expected
  |
  | longer explanation available when compiling with `-explain`
                                                                                                                                                                                                                                                     
scala> val given: Int = 1
-- [E040] Syntax Error: --------------------------------------------------------
1 |val given: Int = 1
  |         ^
  |         an identifier expected, but ':' found
  |
  | longer explanation available when compiling with `-explain` 

Does this PR introduce any user-facing change?

No

How was this patch tested?

Pass GitHub Actions

Was this patch authored or co-authored using generative AI tooling?

No

[LuciferYang]

Merged into master for Spark 4.0. Thanks @HyukjinKwon

[beliefer]

LGTM later.