Support `dolt read-tables` for DoltHub remotes. Fix the error message which says new format.

[timsehn]

$ dolt read-tables --dir ../new-db origin main 
Dolt command 'read-tables' is not supported in format __DOLT__

Damn you @andy-wm-arthur and @druvv .

[timsehn]

Unclear how this is passing:

https://github.com/dolthub/dolt/blob/698c9ce2230e1978d6dd44e2580de1cf4cfbe148/integration-tests/bats/remotes.bats#L573

[timsehn]

So starting from a fresh database and remote works.

$ cd test_read_tables 
$ dolt init --fun
Successfully initialized dolt data repository.
$ dolt sql <<SQL                                                              
CREATE TABLE test (
  pk BIGINT NOT NULL COMMENT 'tag:0',
  c1 BIGINT COMMENT 'tag:1',
  c2 BIGINT COMMENT 'tag:2',
  c3 BIGINT COMMENT 'tag:3',
  c4 BIGINT COMMENT 'tag:4',
  c5 BIGINT COMMENT 'tag:5',
  PRIMARY KEY (pk)
);
SQL
$ dolt ls
Tables in working set:
	 test

$ dolt add test
$ dolt commit -am "test commit"
commit pr1fqv2i643rbroq0hg61p9dgihtcobe (HEAD -> main) 
Author: timsehn <[email protected]>
Date:  Wed May 31 15:32:09 -0700 2023

        test commit

$ mkdir ../remote_for_read_tables
$ dolt remote add test-remote file:///Users/timsehn/dolthub/dolt/remote_for_read_tables
$ dolt push                                                                            
Uploaded 1.5 kB of 1.5 kB @ 0 B/s.

$ ls -al ../remote_for_read_tables 
total 24
drwxr-xr-x   7 timsehn  staff   224 May 31 15:36 .
drwxr-xr-x  33 timsehn  staff  1056 May 31 15:35 ..
-rw-------   1 timsehn  staff   321 May 31 15:36 1cbftjjd4t0mi7k7d3kg8i2uihtop22e
-rw-------   1 timsehn  staff  1493 May 31 15:36 5tc639mu6mtghvir0sg7j6gfhjaimf4g
-rw-------   1 timsehn  staff     0 May 31 15:36 LOCK
-rw-------   1 timsehn  staff   179 May 31 15:36 manifest
drwxr-xr-x   2 timsehn  staff    64 May 31 15:35 oldgen
$ dolt read-tables --dir tables_are_read file:///Users/timsehn/dolthub/dolt/remote_for_read_tables main
cloning file:///Users/timsehn/dolthub/dolt/remote_for_read_tables
Retrieving test
Downloaded 2 chunks, 564 B @ 0 B/s.
$ cd tables_are_read 
$ dolt ls
Tables in working set:
	 test

$

Which is why bats works.

[timsehn]

It looks like this is only DoltHub remotes:

$ dolt remote -v
origin https://doltremoteapi.dolthub.com/timsehn/sql_alchemy_demo 
$ dolt read-tables --dir tables_are_read_from_remote_alias origin main                                 
Dolt command 'read-tables' is not supported in format __DOLT__
$ dolt read-tables --dir tables_are_read_from_remote_url https://doltremoteapi.dolthub.com/timsehn/sql_alchemy_demo main
Dolt command 'read-tables' is not supported in format __DOLT__