True when the last item meets the tooltip hover policy and tooltip contents may be submitted. Call EndTooltip() only when true.
BeginItemTooltip() is a shortcut for the 'if (IsItemHovered(ImGuiHoveredFlags.ForTooltip) && BeginTooltip())' idiom.
SetItemTooltip() is a shortcut for the 'if (IsItemHovered(ImGuiHoveredFlags.ForTooltip)) { SetTooltip(...); }' idiom.
Where 'ImGuiHoveredFlags.ForTooltip' itself is a shortcut to use 'style.HoverFlagsForTooltipMouse' or 'style.HoverFlagsForTooltipNav' depending on active input type. For mouse it defaults to 'ImGuiHoveredFlags.Stationary | ImGuiHoveredFlags.DelayShort'.
begin/append a tooltip window if preceding item was hovered.
Begin a tooltip when the preceding item is hovered.