Fix #3852 Annotation do not work without setting initial state

[kasongoyo]

Description

It turned out the annotation plugin cannot draw on the map when
the default configuration is not provided. This commit fix and allow
annotation to work well without default config.

Issues

• Annotation do not work without setting initial state #3852
• ...

Please check if the PR fulfills these requirements

• The commit message follows our guidelines: https://github.com/geosolutions-it/MapStore2/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x", remove the others)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior? (You can also link to an open issue here)
see #3852

What is the new behavior?
see the description section above

Does this PR introduce a breaking change? (check one with "x", remove the other)

• Yes, and I documented them in migration notes
• No

If this PR contains a breaking change, please describe the impact and migration path for existing applications: ...

Other information:

[coveralls]

Coverage increased (+0.03%) to 82.194% when pulling 61ccb36 on kasongoyo:feature/3852 into e470657 on geosolutions-it:master.