Consider migrate to v3 api

[YunYeSAP]

Hi,

I found out that the emarsys api has already realeased the v3 for a while and in this lib we are still using v2

escher-request/src/requestOption.ts

Line 35 in 6a21805

return this.create(host, '/api/v2/internal', rejectUnauthorized);

And it is shown in the response a warning that the v2 version is already deprecated. I wonder is there any plan to migrate the current implementation also to the latest api version? Thanks in advance!