anttp 0.26.0

AntTP is an HTTP server for the Autonomi Network
Update CreatePointerCommand to set the counter when specified

As a Pointer API consumer
I want to be able to create pointers with a target counter number (when specified)
So that I don't have to create a pointer with a default counter

Given UpdatePointerCommand execute function has an example of calling pointer_update_from with a counter
When creating a pointer with a target counter
Then implement a call to pointer_update_from with the counter specified, after the existing call to pointer_create
And only call pointer_update_from when the pointer counter has been provided

Implementation Notes

- Place any unit tests at the bottom of the same file as the associated production code
- Increment patch version of anttp package in Cargo.toml
- Create a copy of this issue description and save to /spec using the name of this issue as the filename (with lower underscore case, starting with the 5 char padded issue number, e.g. 00001_issue_title.txt)
- Update unit tests to validate the changes

Amendments

- update update_pointer_command.rs to also populate properties with counter (when it is provided), in the same way as create_pointer_command.rs