BUG/MEDIUM: mworker/cli: fix pipelined modes on master CLI

BUG/MEDIUM: mworker/cli: fix pipelined modes on master CLI

Since commit 3d93ecc ("BUG/MAJOR: cli: Restore non-interactive mode
behavior with pipelined commands") and commit 598c7f16 ("BUG/MEDIUM:
cli: Warn if pipelined commands are delimited by a \n"), the pipelined
command on the master CLI are either broken or emit warnings depending
on which version.

The reason is that mode applied on the master CLI are saved on the in
the current CLI session, and then reinserted for each pipelined command,
however, these commande were inserted as new lines.

For example:

 "@1; expert-mode on; debug dev log foo; debug dev log bar"

 Would be sent as:

  "expert mode on\ndebug dev log foo"
  "expert mode on\ndebug dev log bar"

This patch fixes the issue by using the new ci_insert() function which
inserts a string instead of a newline, and the command are now suffixed
by ';' upon insertion allowing a correct pipelined command chain.

This must be backported with the previous commit introducing ci_insert()
in every stable version.

This is broken since the 3.0 version, but it emits a warning in every
version below, because 598c7f164 was backported.