Rework the Flare Gun & add a Security Shell Gun. (#32829)

Rework the Flare Gun & add a Security Shell Gun. (#32829)

* Rework flaregun and add security shell gun

* Make flare gun twice as likely to appear in emergency lockers

* Security shell gun can now fire lethal shells like the flare gun used to be able to.

* Rebalance the sec shell gun material cost to primarily be steel instead of plastic

* Define the ShellShotgunLight tag in tags.yml

* Leave the no lethal shells for normal flareguns to a different PR.

* Move a comment to re-run checks.

* Bye bye lethal shells from plastic guns.

* Fix weird whitespace issue.

* Make the sec shell gun inherit the normal flare gun.

* Remove the rack verb and update the sec shell gun description

* Remove the ability to fire lethals from flare guns, pending blowing up the gun

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Co-authored-by: SlamBamActionman <slambamactionman@gmail.com>