Prop 301: No longer vote on RecommendedPackages

This is the first half of implementing proposal 301. The
RecommendedPackages torrc option is marked as obsolete and
the test cases for the option removed. Additionally, the code relating
to generating and formatting package lines in votes is removed.

These lines may still appear in votes from other directory authorities
running earlier versions of the code and so consensuses may still
contain package lines. A new consensus method will be needed to stop
including package lines in consensuses.

Fixes: #28465