Allow to activate trailing delimiter for CSV parser

[stefan-korn]

User Story

The csv paser library allows for a "traling delimiter" to be activated.

Currently it is not possible to activate this through the DKAN implementation.

Currently the parser configuration can be changed via ImportService::EVENT_CONFIGURE_PARSER, see #3864 .

It would be nice to be able to activate the trailing delimiter through this mechanism too.

Proposing to introduce a parser configuration setting for this. Setting this to FALSE by default , will not change the current behavior, but allow for changing via Event Subscriber if desired.

Acceptance Criteria

Trailing delimiter can be changed via ImportService::EVENT_CONFIGURE_PARSER.

[dafeder]

Sounds good. See PR comments.