feat: Support regular expressions in attributed_string_type

[siegfriedweber]

Description

• Attribute regex added to the macro attributed_string_type.
  • The regular expression is checked when deserializing.
  • If only one regular expression applies then it is added to the pattern of the JsonSchema.
• Attribute min_length added to the macro attributed_string_type.
  • min_length is set in the JsonSchema.
• min_length and max_length are calculated at compile-time. It is not necessary anymore, e.g. to add (max_length = RFC_1123_SUBDOMAIN_MAX_LENGTH) if is_rfc_1123_dns_subdomain_name is set.
• Restriction for non-empty strings removed. The attributes already set correct minimum lengths.
• max function added which works in a const context.
• Attribute is_config_map_key removed from the macro attributed_string_type and replaced with a regular expression.
• Macro attributed_string_type moved from framework to framework::macros::attributed_string_type.
• Macro constant moved from framework to framework::macros::constant.
• Kubernetes types, such as ConfigMapName, moved from framework to framework::types::kubernetes.
• Operator types, such as OperatorName, moved from framework to framework::types::operator.
• Type SecretKey added.
• Type SecretName added.

Part of #1
Required for #76

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

Author

• Changes are OpenShift compatible
• Helm chart can be installed and deployed operator works
• Integration tests passed (for non trivial changes)

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added
• Links to generated (nightly) docs added
• Release note snippet added
• Add type/deprecation label & add to the deprecation schedule
• Add type/experimental label & add to the experimental features tracker