component foot_size doesn't work at all

Verification builds: Release 924386 - 1.5.0.4 BETA
Summary: Using the foot_size component does not work at all and mobs continue to be as mobile as they have always been.

Repro Steps:

1. Download the 'super behavior bug test time' (tm) map from Greg on Slack
2. summon any of the listed mobs
3. tame them with a beetroot (this adds a foot_size of 3)
4. ride it up the 2 block high thing, or make it path up something a block high and see if it jumps or not.

Observed Results:

1. the mob acts normally as if the foot_size was not added.

Expected Results:

1. I use the tame as an easy way to test components, when foot_size is added, the mob should be able to walk up more blocks at a time

all mobs effected by this.