add nutrition facts command

[awaxa]

• this use case should have a shorter command like robot.respond /nutr (.*)$/i
• the response should be formatted more "nicely"

<user> diabot, wfa nutrition popcorn
<diabot> serving size 30 g; total calories  136: fat calories  50; % daily value^*:  ;   total fat  5 g: 8%;        saturated fat  940 mg: 5%;        trans fat  2 g: ;   cholesterol  429 µg: 0%;   sodium  144 mg: 6%;   total carbohydrates  20 g: 7%;        dietary fiber  3 g: 12%;        sugar  4 g: ;   protein  3 g: 5%;    vitamin A  1%   :    calcium  1%   ;    iron  4%   :    vitamin E  2%   ;    thiamin  3%   :    riboflavin  2%   ;    n
<diabot>    magnesium  8%   :    zinc  5%   ; *percent daily values are based on a 2000 calorie diet; (averaged over different types of popcorn)

[awaxa]

basically an improved version of the feature removed by 3588572

[awaxa]

<awaxa> testdiabot: nutr one cup white flour
<testdiabot> serving size 1 cup (138 g) | total calories  481: fat calories  0 | % daily value^*: | total fat  0 g: 0% | saturated fat  0 g: 0% | trans fat  0 g: | cholesterol  0 g: 0% | sodium  0 g: 0% | total carbohydrates  100 g: 33% | dietary fiber  | sugar  4 g: | protein  16 g: 32% | iron  40%   | *percent daily values are based on a 2000 calorie diet
<awaxa> testdiabot: wfa nutrition one cup white flour
<testdiabot> serving size 1 cup (138 g); total calories  481: fat calories  0; % daily value^*:  ;   total fat  0 g: 0%;        saturated fat  0 g: 0%;        trans fat  0 g: ;   cholesterol  0 g: 0%;   sodium  0 g: 0%;   total carbohydrates  100 g: 33%;        dietary fiber  : ;        sugar  4 g: ;   protein  16 g: 32%;    iron  40%   :             ; *percent daily values are based on a 2000 calorie diet

This is indeed the desired improvement. Thanks, @ROBOKiTTY!