[lib][console] rename some console command types to be prefixed with console_

Some of the structures, notably 'cmd', in the lib console stuff are a
little too generically named and have collided with some other code
so prefix the names a bit more cleanly with console_

The change is largely mechanical, and folks with out of tree code can
easily switch by renaming:
cmd -> console_cmd
cmd_args -> console_cmd_args
cmd_block -> console_cmd_block
console_cmd -> console_cmd_func

Apologies if this breaks you but it should be pretty easy to fix.

target/nucleo-f072rb/init.c

@@ -52,7 +52,7 @@ void target_set_debug_led(unsigned int led, bool on) {
     }
 }
 
-static int cmd_i2c_rb(int argc, const cmd_args *argv) {
+static int cmd_i2c_rb(int argc, const console_cmd_args *argv) {
 
     if (argc != 3) {
         printf("usage: i2c_rb <addr> <reg>\n");