DecimalFormat while parsing utilizes DigitList which stores discovered digits into the `digits` array. Currently the resizing approach is to add a constant 100. This approach seems odd and not tied to any particular reasoning, especially considering that the input can be up to the max length of a String for a parse. Thus, we should switch to a resizing approach of multiplying by a constant rather than linear adding. This will help with performance, especially with large inputs since much less time is spent constantly allocating a larger array and copying over elements.