Add variables for safety team, player and id

[mrcaseb]

There are some weird cases where it is not easy to get the correct safety player (which is req. for defensive player stats) so we should add that information via stat id 89 explicitly

[mrcaseb]

Currently we are doing this

nflfastR/R/helper_tidy_play_stats.R

Lines 1054 to 1055 in 76525b0

	} else if (stat_id == 89) {
	row$safety <- 1

[mrcaseb]

For 2020, stat id 89 delivers 24 safeties some of which are not counted for a specific player because of plays like this:

"(9:18) (Shotgun) 1-K.Murray pass short middle to 10-D.Hopkins to ARI 10 for 8 yards (50-K.Wright). PENALTY on ARI-64-J.Sweezy, Offensive Holding, 2 yards, enforced in End Zone, SAFETY - No Play."

The overall Number of 24 and the respective teams are correct so it shopuld be fine to use stat id 89