CUFF PRESSURE tab should display the counts of CUFF1 scans with pressure recorded

[psadil]

Over the boxplots on the CUFF PRESSURE tab, there are numbers written.

It seems like those numbers refer to the number of participants from each site/session, but I think it may be more informative to show the number of CUFF1 scans that have pressure recorded.

For example, here is a count of subject ids by visit and site in the imaging log as of this morning

site	visit	n
NS	V1	237
NS	V3	138
RU	V1	1
SH	V1	51
SH	V3	37
UC	V1	130
UC	V3	76
UI	V1	314
UI	V3	217
UM	V1	269
UM	V3	184
WS	V1	51
WS	V3	31

Those numbers match the numbers in the cuff plot (well, almost e.g., SH V1 is off by one -- see #14)

Here are the counts broken down by whether CUFF1 is indicated (showing V1 only, for space)

site	visit	fMRI Individualized Pressure Indicated	n
NS	V1	FALSE	94
NS	V1	TRUE	143
RU	V1	TRUE	1
SH	V1	FALSE	2
SH	V1	TRUE	49
UC	V1	FALSE	34
UC	V1	TRUE	96
UI	V1	FALSE	65
UI	V1	TRUE	249
UM	V1	FALSE	91
UM	V1	TRUE	178
WS	V1	FALSE	14
WS	V1	TRUE	3

So, for example, of the 237 NS V1 participants, 94 do not have CUFF1 scan (fMRI Individualized Pressure Indicated == FALSE) and so shouldn't contribute data to the boxplot.

[psadil]

FWIW, a change was made recently to how the imaging-log-latest.csv handles cases with where fMRI Individualized Pressure Indicated == FALSE, such that those cases now have "na" in the "Cuff1 Applied Pressure" column. I'm not sure how that will affect the counts and display