Add: [Script] GSIndustry.GetConstructionDate() method (#11145)

(cherry picked from commit ce9305a5ee)

src/script/api/script_industry.hpp

@@ -82,6 +82,15 @@ public:
 	 */
 	static std::optional<std::string> GetName(IndustryID industry_id);
 
+	/**
+	 * Get the construction date of an industry.
+	 * @param industry_id The index of the industry.
+	 * @pre IsValidIndustry(industry_id).
+	 * @return Date the industry was constructed.
+	 * @api -ai
+	 */
+	static ScriptDate::Date GetConstructionDate(IndustryID industry_id);
+
 	/**
 	 * Set the custom text of an industry, shown in the GUI.
 	 * @param industry_id The industry to set the custom text of.