Rename Label & RichTextLabel.percent_visible to visible_ratio

[Mickeon]

Closes godotengine/godot-proposals#4978.

For Label & RichTextLabel:
percent_visible -> visible_ratio

This way its meaning is much clearer, and now the property can more tidily be organised with the similar visible_characters.

Also updates the Documentation of both visible_characters and visible_ratio considerably, to better describe what they do and improve consistency between the two Classes.

[akien-mga]

For the record there's also percent_visible in ProgressBar:

$ rg 'percent_visible' -g'!*.po*'
scene/gui/progress_bar.h
39:     bool percent_visible = true;
57:     void set_percent_visible(bool p_visible);
58:     bool is_percent_visible() const;

scene/gui/progress_bar.cpp
44:     if (percent_visible) {
103:                    if (percent_visible) {
128:void ProgressBar::set_percent_visible(bool p_visible) {
129:    if (percent_visible == p_visible) {
132:    percent_visible = p_visible;
137:bool ProgressBar::is_percent_visible() const {
138:    return percent_visible;
144:    ClassDB::bind_method(D_METHOD("set_percent_visible", "visible"), &ProgressBar::set_percent_visible);
145:    ClassDB::bind_method(D_METHOD("is_percent_visible"), &ProgressBar::is_percent_visible);
148:    ADD_PROPERTY(PropertyInfo(Variant::BOOL, "percent_visible"), "set_percent_visible", "is_percent_visible");

doc/classes/ProgressBar.xml
15:             <member name="percent_visible" type="bool" setter="set_percent_visible" getter="is_percent_visible" default="true">
47:                     Font used to draw the fill percentage if [member percent_visible] is [code]true[/code].
50:                     Font size used to draw the fill percentage if [member percent_visible] is [code]true[/code].

editor/plugins/animation_blend_tree_editor_plugin.cpp
236:                    pb->set_percent_visible(false);

It could maybe be renamed too for consistency, though I don't know if visible_ratio is such a good name for it. Maybe fill_ratio since it's about filling a progress bar?

Otherwise this PR seems fine as is.

[akien-mga]

Looks good for the Label and RichTextLabel changes.

[akien-mga]

Thanks!

[Mickeon]

@akien-mga It could maybe be renamed too for consistency, though I don't know if visible_ratio is such a good name for it. Maybe fill_ratio since it's about filling a progress bar?

Most confusingly, that property is not the visible percentage, it's actually a boolean that when set to true, displays the completion percentage at the center of the ProgressBar.

[akien-mga]

Oh ok, then maybe it could be renamed to show_percentage?

[Mickeon]

Sounds pretty good to me, coming soon!