Make some more plot changes

[KristinaRiemer]

• [x] Relative weight, make sure all categories show up even with no data
• [x] Change CPUE legend to match length frequency
• [x] Relative weight remove 50 lineand make 100 line darker
• [x] Relative weight set y-axis range to 50 and 160 (make sure values within range)
• [x] Return message if UU data includes relative weight above 160 or below 50?
• [x] Change all plot colors to black and white (make points bigger)
• [x] Between space between legend labels for length frequency (if possible)
• [x] Caption improvements: change capitalizing to normal, remove "graph", change rel weight caption to match x-axis and change x-axis to match length frequency's
• [x] Move rel weight legend to right hand side
• [x] Remove rel weight N values

[KristinaRiemer]

Relative weight mean range is 50.4 to 159.6

[KristinaRiemer]

Most relative weight values in standardized dataset are less than 110

[KristinaRiemer]

Closed by #39