EncodingUtils constructor Null safety

1. base32
2. encodings
3. EncodingUtils
4. EncodingUtils constructor

EncodingUtils class

1. Constructors
2. EncodingUtils
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static methods
12. getChars
13. getDecodeMap
14. getPadded
15. getRegex