2023.2 API changes: display name

[huyz]

Per https://plugins.jetbrains.com/docs/intellij/api-changes-list-2023.html?section=English#intellij-platform-20232

Specify displayName/key for Configurable

To improve performance, provide either attribute for com.intellij.applicationConfigurable or com.intellij.projectConfigurable extension point (see Settings Guide).

Otherwise, the IDE gives out exceptions:

com.intellij.diagnostic.PluginException: No display name is specified for configurable io.heidou.codesearch.settings.CodeSearchConfigurable in xml file;
specify it using 'displayName' or 'key' attribute to avoid necessity to load the configurable class when Settings dialog is opened [Plugin: io.heidou.codesearch]
	at com.intellij.openapi.options.ex.ConfigurableWrapper.getDisplayName(ConfigurableWrapper.java:156)
	at com.intellij.ide.util.gotoByName.GotoActionModel.lambda$new$0(GotoActionModel.java:81)
	at com.intellij.openapi.util.NotNullLazyValue$4.compute(NotNullLazyValue.java:120)
	at com.intellij.openapi.util.NotNullLazyValue$4.getValue(NotNullLazyValue.java:105)
	at com.intellij.ide.util.gotoByName.GotoActionModel.getConfigurablesNames(GotoActionModel.java:378)
	at com.intellij.ide.util.gotoByName.GotoActionItemProvider.processOptions(GotoActionItemProvider.java:148)
	at com.intellij.ide.util.gotoByName.GotoActionItemProvider.filterElements(GotoActionItemProvider.java:94)
	at com.intellij.ide.actions.searcheverywhere.ActionSearchEverywhereContributor.lambda$fetchWeightedElements$4(ActionSearchEverywhereContributor.java:137)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$executeProcessUnderProgress$13(CoreProgressManager.java:604)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:679)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computeUnderProgress(CoreProgressManager.java:635)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:603)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:61)
	at com.intellij.ide.actions.searcheverywhere.ActionSearchEverywhereContributor.fetchWeightedElements(ActionSearchEverywhereContributor.java:136)
	at com.intellij.ide.actions.searcheverywhere.MixedResultsSearcher$ContributorSearchTask.run(MixedResultsSearcher.java:184)
	at com.intellij.util.ConcurrencyUtil.runUnderThreadName(ConcurrencyUtil.java:218)
	at com.intellij.util.ConcurrencyUtil.lambda$underThreadNameRunnable$3(ConcurrencyUtil.java:206)
	at com.intellij.openapi.application.impl.ApplicationImpl$2.run(ApplicationImpl.java:272)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:702)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:699)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:699)
	at java.base/java.lang.Thread.run(Thread.java:833)