feat: implement attribute conversion util

Description

Util for attribute conversion between external and internal key representation described in: https://perunaai.atlassian.net/browse/STR-1405

How to test

Run the tests in /src/test/java/perun.connector/utils/AttributeUtilsTest

Author's checklist

• I have followed the contribution guidelines
• This MR has been tested or does not change functionality
• I have added relevant merge request dependencies (if this MR has any)
• I have added the correct labels
• I have assigned reviewers (if any are relevant)
• I have edited the documentation (if the changes require it) or I have noted the need for the change if I do not have access to the documentation
• I have marked all introduced BREAKING CHANGES or necessary DEPLOYMENT NOTES in the commit message(s)

Reviewer's checklist

• This MR has been tested or does not change functionality
• This MR has correct commit message format

Other information

Some changes in config format were needed to accommodate some caveats of Spring Boot. For example colons in yaml keys are removed if not escaped by square brackets like this:

"[urn:perun:vo:attribute-def:def:blockManualMemberAdding]":
      id: 3638
      type: java.lang.Boolean
      ldap:

Also, configuration profiles have to be named like application-{profile_name}.yml so I renamed the remaining configs to kebab-case to maintain some naming convention within all configs.

I did not mark these changes as breaking changes, since this configuration is presently under development and not used by anyone. I considered those configs to be mere placeholders.

Related issues

closes STR-1393