SPINEL_PROP_MESHCOP_COMMISSIONER_JOINERS value

Format `A(t(t(E|CX)UL))` - get, insert or remove. Required capability: SPINEL_CAP_THREAD_COMMISSIONER Data per array entry is: `t()` | `t(E)` | `t(CX)` : Joiner info struct (formatting varies). - `t()` or empty struct indicates any joiner. - `t(E)` specifies the Joiner EUI-64. - `t(CX) specifies Joiner Discerner, `C` is Discerner length (in bits), and `X` is Discerner value. The struct is followed by: `L` : Timeout after which to remove Joiner (when written should be in seconds, when read is in milliseconds) `U` : PSKd For CMD_PROP_VALUE_REMOVE the timeout and PSKd are optional.