Feature summary (what you would like to be able to do and where):
When blocking a range, Special:Block normalizes the range by setting the least significant parts of the prefix to their lowest possible value. For example, 198.73.209.123/24 becomes 198.73.209.0/24, 2001:0db8:0123:4567:89ab:cdef:1234:5678/64 becomes 2001:DB8:123:4567:0:0:0:0/64. Special:Contributions should do the same when showing range contributions.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):

• https://commons.wikimedia.org/w/index.php?target=198.73.209.123%2F24&namespace=all&tagfilter=&start=&end=&limit=50&title=Special%3AContributions (example)

The current behavior is confusing, especially for editors who don't have a full understanding of CDIR notation. It is not always clear that two ranges are the same, because they can have different representations. This is especially apparent when dealing with smaller ranges that do not affect an entire octet, like an IPv4 /27. It gets even worse dealing with IPv6.

Benefits (why should this be implemented?):
MediaWiki should treat IP ranges consistently.