Add new KiwiJdbc utility to return optionally stripped string, or null if blank

[sleberknight]

Add a new method in KiwiJdbc to return null if a string obtained from calling ResultSet#getString is blank (i.e. null, empty string, or whitespace-only). If the string is not blank, then use an enum argument to decide whether to strip any leading or trailing whitespace from the original string.

Signature:

@Nullable
String stringOrNullIfBlank(ResultSet rs, String columnName, TrimStrategy strategy)

New enum class to describe whitespace handling

Create a simple enum that describes whether or not to strip leading and trailing whitespace.

enum TrimStrategy {
     PRESERVE, REMOVE
}

I am not wed to TrimStrategy as the name. Since I could not think of a decent name, I asked ChatGPT and here is what it came up with:

A good name for a Java enum that describes whether a String should have leading and trailing whitespace removed or not could be something clear and self-explanatory. Here are a few suggestions:

1. WhitespaceHandling - This enum could have values like TRIM, KEEP, or NONE to indicate different handling options.

2. StringTrimOption - This enum could include options like TRIM, NO_TRIM, or KEEP_WHITESPACE.

3. WhitespacePolicy - This enum could represent policies for handling whitespace, with values like REMOVE, PRESERVE, or IGNORE.

4. TrimmingStrategy - This enum might include strategies like TRIM_WHITESPACE, PRESERVE_WHITESPACE, or LEAVE_WHITESPACE.

5. WhitespaceMode - This enum could define modes like TRIM_LEADING_AND_TRAILING, PRESERVE_LEADING_AND_TRAILING, or NO_WHITESPACE_HANDLING.

Choose a name that fits well with your project's coding style and makes the purpose of the enum clear to developers who will use it in their code. The key is to keep it descriptive and easy to understand.

Pretty good names!

This method can delegate to the new methods created in #1047 or #1048.

[sleberknight]

I think I prefer StringTrimOption or just TrimOption to TrimStrategy. This makes it consistent with the BooleanConversionOption enum created by #1053 (and #1055)