Bug 1610732 part 2. Throw the right exception when a user.id value is too long. r=jcj

The test changes are for the following reasons:

1. Removing the "empty ArrayBuffer" test: I don't see anything obvious in the

spec that would cause that to reject before prompting the user, and in fact it
does not do that in browsers. All browsers time out on that line.

2. Removing the "name is object" test: This test is wrong. Passing {} where a

string is expected in IDL will come out as the string "[object Object]" on the
other side, and that seems like a perfectly valid name.

3. Removing the "name is null" test: This test is wrong. Passing null where a

string is expected in IDL will come out as the string "null" on the other side,
and that seems like a perfectly valid name.

4. Removing the "name is empty" test: I don't see anything obvious in the

spec that would cause that to reject before prompting the user.

5. Removing the various "icon is whatever" tests: I don't see anything obvious in the

spec that would cause that to reject before prompting the user.

6. Removing the various "displayName is whatever" tests: the same reasoning as

for the coresponding "name is whatever" tests applies.

Differential Revision: https://phabricator.services.mozilla.com/D60685