style: unify identifier naming per updated conventions

Automated with clang-tidy readability-identifier-naming (config added to
.clang-tidy) plus scripted passes, per the updated rules now documented
in CONTRIBUTING.md:

- types (class/struct/enum/alias/template params): PascalCase
- functions, variables, members: snake_case (incl. rational -> Rational)
- private/protected members: trailing underscore; static member
  variables likewise (instance_, available_themes_)
- constants and enum values: snake_case (kLinear -> k_linear,
  F32P -> f32p); ALL_CAPS reserved for macros
- macros: OAK_ prefix (OLIVE_ADD_TEST/OLIVE_ASSERT/OLIVE_CONFIG ->
  OAK_ADD_TEST/OAK_ASSERT/OAK_CONFIG, GL_PREAMBLE -> OAK_GL_PREAMBLE,
  include guards -> OAK_*)
- file names: all lowercase (Current/Plugin/OliveHost/OliveClip/
  OlivePluginInstance -> current/plugin/olivehost/oliveclip/
  oliveplugininstance)
- getters share the member name sans underscore, setters set_foo()
- Qt and third-party (OpenFX) virtual overrides and framework callbacks
  keep their original names (exempt in .clang-tidy)

Manual follow-ups required where automation could not reach:
- string-based QMetaObject/SIGNAL/SLOT references updated to renamed
  methods (AddTask, CreatedFile, DeleteSpecificFile, moveSelectionUp, ...)
- macro bodies referencing renamed methods (OLIVE_CONFIG,
  NODE_DEFAULT_DESTRUCTOR, MANAGEDDISPLAYWIDGET_*)
- self-shadowing locals renamed where signals/methods became same-named
  (size_changed, worker_count, selected_items, import param, filters)
- third_party OFX member/namespace usages restored (OFX::Host::*,
  _created, _clipPrefsDirty, createInstance, clearPersistentMessage)
- STL protocol aliases restored (const_iterator) with .clang-tidy
  ignore rules; qHash overloads restored

Full build and test suite pass: ctest 4/4, ~1960 gtest cases green.

app/node/block/subtitle/subtitle.cpp

@@ -26,30 +26,30 @@ namespace olive
 
 #define super ClipBlock
 
-const QString SubtitleBlock::kTextIn = QStringLiteral("text_in");
+const QString SubtitleBlock::k_text_in = QStringLiteral("text_in");
 
 SubtitleBlock::SubtitleBlock()
 {
-	AddInput(kTextIn, NodeValue::kText,
-			 InputFlags(kInputFlagNotConnectable | kInputFlagNotKeyframable));
+	add_input(k_text_in, NodeValue::k_text,
+			 InputFlags(k_input_flag_not_connectable | k_input_flag_not_keyframable));
 
-	SetInputFlag(kBufferIn, kInputFlagHidden);
-	SetInputFlag(kLengthInput, kInputFlagHidden);
-	SetInputFlag(kMediaInInput, kInputFlagHidden);
-	SetInputFlag(kSpeedInput, kInputFlagHidden);
-	SetInputFlag(kReverseInput, kInputFlagHidden);
-	SetInputFlag(kMaintainAudioPitchInput, kInputFlagHidden);
+	set_input_flag(k_buffer_in, k_input_flag_hidden);
+	set_input_flag(k_length_input, k_input_flag_hidden);
+	set_input_flag(k_media_in_input, k_input_flag_hidden);
+	set_input_flag(k_speed_input, k_input_flag_hidden);
+	set_input_flag(k_reverse_input, k_input_flag_hidden);
+	set_input_flag(k_maintain_audio_pitch_input, k_input_flag_hidden);
 
 	// Undo block flag that hides in param view
-	SetFlag(kDontShowInParamView, false);
+	set_flag(k_dont_show_in_param_view, false);
 }
 
-QString SubtitleBlock::Name() const
+QString SubtitleBlock::name() const
 {
-	if (GetText().isEmpty()) {
+	if (get_text().isEmpty()) {
 		return tr("Subtitle");
 	} else {
-		return GetText();
+		return get_text();
 	}
 }
 
@@ -58,17 +58,17 @@ QString SubtitleBlock::id() const
 	return QStringLiteral("org.olivevideoeditor.Olive.subtitle");
 }
 
-QString SubtitleBlock::Description() const
+QString SubtitleBlock::description() const
 {
 	return tr(
 		"A time-based node representing a single subtitle element for a certain period of time.");
 }
 
-void SubtitleBlock::Retranslate()
+void SubtitleBlock::retranslate()
 {
-	super::Retranslate();
+	super::retranslate();
 
-	SetInputName(kTextIn, tr("Text"));
+	set_input_name(k_text_in, tr("Text"));
 }
 
 }