Table.js uses `throwMessageException` too often, and with placeholder messages far too often

[jpolitz]

The name of the column ought to be reported, and probably also the names of the existing columns.

[blerner]

I'd generalize this: there are a lot of uses of ffi.throwMessageException in table.js that use hyphenated-placeholder-messages, and they all ought to be updated. (E.g., "column-name-exists", "add-row-length", etc.)

[blerner]

The two uses of throwMessageException dealing with Rows could throw duplicate-column or column-not-found errors instead, if those errors were generalized not to be hard-coded to tables only. These errors also require too many srclocs, which we may not have at runtime.

openTable has four uses, which might be esoteric enough to stay as simple messages.

getRowContentAsGetter should probably throw a column-not-found error.

multiOrder needs a new error.

The order-by, order-by-columns, multi-order, column, filter-by, get-column, select-columns methods should throw column-not-found. (Is get-column a synonym for column?)

add-column should throw a duplicate-column

add-row should throw row-length-mismatch

row-n and column-n could throw an index-out-of-bounds error, of some sort

stack and reduce need new errors

[jpolitz]

Also build-column.

[schanzer]

Now that I'm testing this with actual kids (albeit ultra high-performing kids), I'm really seeing the need for at least no-such-column to be improved. This one is coming up a lot, and tripping kids up.