Fix error message in tiledb_array()

[cgiachalis]

This PR fixes an error message in tiledb_array() to reflect the right source ('selected_points' not 'selected_ranges'). Also, it cleans up various minor typos.

library(tiledb)
df <- data.frame(key=letters[1:5], val=c(1:5))
uri <- tempfile()
fromDataFrame(df, uri, col_index = 1)

# selected_points accepts a vector but we passed a matrix
tiledb_array(uri, selected_points = list(key = cbind(0, 1)))[]
#> Error in validObject(.Object): invalid class "tiledb_array" object: Element '1' of 'selected_ranges' is not a vector.
                                                                                                 ^------------ Should be 'selected_points'

After

#> Error in validObject(.Object) : 
  invalid class “tiledb_array” object: Element '1' of 'selected_points' is not a vector.

[mojaveazure]

Looks good, thanks for taking care of this! Can you bump the development version in the DESCRIPTION, add a changelog item to NEWS.md before merging?

[cgiachalis]

add a changelog item to NEWS.md before merging?

@mojaveazure That's done and ready for merging.

[mojaveazure]

@cgiachalis Great, thank you!