Provide promisified api out-of-the-box

[kibertoad]

Current behavior

Users have to promisify node-freshdesk-api

Expected behavior

Promise-based API is available out-of-the-box

More details

No additional libraries are needed for this, Node has native solution: https://nodejs.org/api/util.html#utilpromisifyoriginal

[arjunkomath]

I can look into this.

[kibertoad]

I can do this together with undici conversion then

[arjunkomath]

@kibertoad Thanks, if the PR gets too big I'd prefer if we break them into two separate PRs.

[kibertoad]

@arjunkomath Effort required for this was too big, I don't think I can realistically handle that in the end, unfortunately :-/