[Feature request]: Allow mqtt topics to end with number only level

[magmilo]

Is your feature request related to a problem? Please describe

I have set up a zigbee2mqtt node and would like to be able to configure topics that end with a device id. This is impossible, as zigbee2mqtt disallows topics to end on a string of numbers without any characters

Describe the solution you'd like

Numbers should be allowed as the last characters in the topic string. It complies with mqtt specifications

Describe alternatives you've considered

I'm currently adding a specific character at the end of my topic names

Additional context

none

[LaurentChardin]

Can you provide some examples of what you are trying to do ?