Fixing issue where custom default value without a 'value=' within the script would return an empty string.

[travist]

Link to Jira Ticket

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

Description

There was a bug that I fixed in the previous pr ( #6048 ) that was attempting to protect the case where no "value=" is provided within the customDefaultValue as well as the calculatedValue evaluations. Previously, this would return an empty string, which would then set the defaultValue to an empty string causing major problems for incompatible datatypes.

This PR reverts the "fix" from the previous PR and implements a better change which is to default the value passed to the evaluation context with the current dataValue of the component, which is what it should be. This way, if the user does not provide a "value=" within the evaluation, then it will return the current dataValue.

Breaking Changes / Backwards Compatibility

This may break any implementations that previously expected an empty string return as the result of customDefaultValue.

Dependencies

None

How has this PR been tested?

Manual testing

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