Alphabet (e.g. a white space) for intent identifiers?
Ask Anaconda: What is the grammar, meaning, who does define them?
Anaconda: We get "system purpose" data from a subscription manager, user
selects one, we push the selection back into the manager. Ask DNF where they
get intents from. We install packages and modules with DNF.
DNF: We do not implement it, we don't want to detect intents.
Anaconda: Anaconda/subscription manager allows setting a system purpose as an
arbitrary string. Currently the value is also a display string. Without
localization. Some values are in /etc/rhsm/syspurpose/valid_fields.json.

Intents were deprecated
<https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/RXDP2WMPR3HHBRTQAKPSTRU6KABTJSMA/#JDN2FHCDR6BNPCL4EQKRN3UK54UZOGNN>.
Nobody used them and DNF did not implement them. There is no
distribution-agnostic way of delivering intents to DNF.

DECISION
========
- Allow an arbitrary string. An empty string equals to undefined value.
- Removed without a replacement.
