Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones via Direct Cyclocondensation Reaction Using Chromium (III) Coordinated to 2‐[(2‐Amino‐ethylimino) methyl]‐6‐methoxyphenol Decorated Fe 3 O 4 @Silicapropyl as an Efficient and Magnetically Recoverable Nanocatalyst