Misc Function fixes

[srkukarni]

Motivation

This pr does a couple of minor fixes

1. Collect input topics from the function details spec:- Currently source is referred before creating the context, while source creation itself needs the context. This circular dependency is removed by making context creation independent of source.
2. Catch all errors during source/sink close since its user code:- Sink/Source code is external/user code, thus any errors caught need to be caught.

Modifications

Describe the modifications you've done.

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API: (yes / no)
• The schema: (yes / no / don't know)
• The default values of configurations: (yes / no)
• The wire protocol: (yes / no)
• The rest endpoints: (yes / no)
• The admin cli options: (yes / no)
• Anything that affects deployment: (yes / no / don't know)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)
• If a feature is not applicable for documentation, explain why?
• If a feature is not documented yet in this PR, please create a followup issue for adding the documentation

[srkukarni]

run java8 tests

[srkukarni]

run java8 tests

[merlimat]

Merged in 2.3.1 at
6e8320a