FIO-7954: fixed translations

[TanyaGashtold]

Link to Jira Ticket

https://formio.atlassian.net/browse/FIO-7954

Description

What changed?

• refactored translations and moved all hardcoded translated strings to single file;
• added ability to extend default translations by formio modules using Formio.use
• added backward compatibility for cases where the entire phrase is used as a key for translation

Dependencies

https://github.com/formio/premium/pull/364
https://github.com/formio/reporting/pull/52
formio/bootstrap#121
https://github.com/formio/grid/pull/64

How has this PR been tested?

Manually + tests

Checklist:

• I have completed the above PR template
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new warnings
• My changes include tests that prove my fix is effective (or that my feature works as intended)
• New and existing unit/integration tests pass locally with my changes
• Any dependent changes have corresponding PRs that are listed above