Add UseLocaleWithCaseConversions recipe for STR02-J (#78)

[kush2439p]

What does this PR do?

Adds a new recipe, UseLocaleWithCaseConversions, implementing STR02-J: it rewrites
String#toLowerCase() / String#toUpperCase() calls that don't specify a Locale to
explicitly pass Locale.ROOT (or a user-configured locale). This avoids locale-dependent
case-conversion bugs — e.g. converting "I" to lowercase under a Turkish locale yields a
dotless ı instead of the expected i.

• Closes Specify an appropriate locale when comparing locale-dependent data.STR02-J #78

Changes

• UseLocaleWithCaseConversions: new recipe with an optional @Option locale
  (defaults to ROOT if not provided, per the issue's request), using MethodMatcher +
  JavaTemplate to rewrite the method call and maybeAddImport for the Locale import.
• Tests: covers toLowerCase() → toLowerCase(Locale.ROOT), toUpperCase() →
  toUpperCase(Locale.ROOT), no-op when a Locale is already specified, and a
  configured non-default locale.
• common-static-analysis.yml: registered the recipe, but commented out / opt-in,
  since it changes case-conversion semantics (not just style) for one of the most
  commonly called String methods. Happy to discuss making it active-by-default if
  maintainers feel differently.

Example

// before
str.toLowerCase();

// after
str.toLowerCase(Locale.ROOT);

Backward compatibility

Since the recipe is registered as opt-in (commented out in common-static-analysis.yml),
existing users of CommonStaticAnalysis see no behavior change unless they explicitly
activate this recipe.

[kush2439p]

Opened a PR for this: adds UseLocaleWithCaseConversions, a recipe that rewrites
String#toLowerCase()/toUpperCase() calls without a Locale to use Locale.ROOT by
default, with an @Option to configure a different locale — per the original ask in this
issue. Registered it as opt-in in common-static-analysis.yml for now since it's a
semantic (not just stylistic) change; open to feedback on whether it should be enabled
by default. Tests included, happy to adjust based on review.