arrow

GH-39191: [R] throw error when `string_replace` is passed vector of values in `pattern` (#39219)



### Rationale for this change
See #39191 This PR will hopefully throw an informative error message to let the user know that while the stringr::str_replace_all function can handle a named vector of values as the pattern argument, the arrow R package implementation cannot.  

### What changes are included in this PR?
- [ ] add tests for passing vector to the pattern argument
- [ ] add check for length > 1 to the string replace bindings

### Are these changes tested?
yes (though I need help!)

### Are there any user-facing changes?
 yes. Hopefully the user will be alerted by an informative error message that they cannot pass a vector to the pattern argument. No breaking changes are expected.

* Closes: #39191

Authored-by: Abram B. Fleishman <abram@conservationmetrics.com>
Signed-off-by: Nic Crane <thisisnic@gmail.com>