Binary location

The cli does not require root or elevated privilege, but the cli exe is installed in /usr/sbin and is not in the PATH of a normal user.
Running the cli as root should not be required. I suggest installing the cosmian cli in the /usr/bin directory.

Step to reproduce : 
```
#  dpkg -i cosmian-cli_1.7.0-1_amd64.deb
$ cosmian
command not found: cosmian
```