cmd: fix input/output unstripped definition quotes

With the following config:

    set $abc "wayland wayland "
    set $def "0:0:wayland-seat0"

The following command would fail to be executed:

    swaymsg -- output '$abc' scale 2
    swaymsg -- input '$def' repeat_rate 2

The definition `$abc` is replaced with its content, including the quotes,
which fails to match real output names. Same for `$def`

We now strip quotes early in the output command.

The behaviour was inconsistent between config_command() and execute_command().
* config_command() strips quotes before do_var_replacement() and also after,
  under some conditions.
* execute_command() strips them only before.

execute_command() is run after receiving swaymsg command hence the
failing example mentioned above.

Since we now strip quotes in cmd_output and cmd_input we prevent
config_command() from stripping them twice.

sway/commands.c

@@ -403,6 +403,8 @@ struct cmd_results *config_command(char *exec, char **new_block) {
 				&& handler->handle != cmd_bindswitch
 				&& handler->handle != cmd_set
 				&& handler->handle != cmd_for_window
+				&& handler->handle != cmd_output
+				&& handler->handle != cmd_input
 				&& (*argv[i] == '\"' || *argv[i] == '\'')) {
 			strip_quotes(argv[i]);
 		}

sway/commands/input.c

@@ -51,6 +51,13 @@ struct cmd_results *cmd_input(int argc, char **argv) {
 		return error;
 	}
 
+	// Commands from config_command() & execute_command() don't handle quotes the same way
+	for (int i = 0; i < argc; ++i) {
+		if (*argv[i] == '\"' || *argv[i] == '\'') {
+			strip_quotes(argv[i]);
+		}
+	}
+
 	sway_log(SWAY_DEBUG, "entering input block: %s", argv[0]);
 
 	config->handler_context.input_config = new_input_config(argv[0]);

sway/commands/output.c

@@ -2,6 +2,7 @@
 #include "sway/commands.h"
 #include "sway/config.h"
 #include "sway/output.h"
+#include "stringop.h"
 #include "list.h"
 #include "log.h"
 
@@ -39,6 +40,13 @@ struct cmd_results *cmd_output(int argc, char **argv) {
 				"Refusing to configure the no op output");
 	}
 
+	// Commands from config_command() & execute_command() don't handle quotes the same way
+	for (int i = 0; i < argc; ++i) {
+		if (*argv[i] == '\"' || *argv[i] == '\'') {
+			strip_quotes(argv[i]);
+		}
+	}
+
 	struct output_config *output = NULL;
 	if (strcmp(argv[0], "-") == 0 || strcmp(argv[0], "--") == 0) {
 		if (config->reading) {