feat(cmf): allow bootstrap without settings

[jsomsanith-tlnd]

What is the problem this PR is trying to solve?
Settings has been the heart of cmf since the beginning.
But we should allow to write app without injection everywhere.

What is the chosen solution to this problem?
cmf.bootstrap() doesn't fetch and dispatch settings if not settingsURL is provided

Please check if the PR fulfills these requirements

• The PR commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features) And non reg done before need review
• Docs have been added / updated (for bug fixes / features)
• Related design / discussions / pages (not in jira), if any, are all linked or available in the PR

[x] This PR introduces a breaking change

• PR feat(cmf): allow bootstrap without settings #2110

cmf.bootstrap doesn't have a default settingsURL value anymore. Without settingsURL, no settings will be fetched.

To set back the previous behavior, you just need to pass the settingsURL

// before
cmf.bootstrap({
    // attributes without settingsURL
});

// after
cmf.bootstrap({
    settingsURL: '/settings.json'
});

[build-travis-ci]

Demo is available here

[build-travis-ci]

Demo is available here