Reformat match matrix

[AlexNikic]

Currently when you call match_instruments(instrument), the object match_response$matches is in the form of a list of lists. A lot of users are using boiler plate code to reformat this into a readable dataframe object.

df <- data.frame(match_response$matches[[1]])
for (x in seq_along(match_response$matches)) {
    df[x, ] <- match_response$matches[[x]]
}

colnames(df) <- lapply(match_response$questions, function(x) paste(x$question_no, x$question_text, sep = " "))
rownames(df) <- lapply(match_response$questions, function(x) paste(x$question_no, x$question_text, sep = " "))

It would be good to have this built into the library. Then we can visualise the dataframe using heatmap(as.matrix(df)). This can also be included in any example or tutorial notebooks.