reporting-20: don't display soft credits by default when force=1

[MegaphoneJon]

https://lab.civicrm.org/dev/report/issues/20

Overview

When you load the Contribution Detail report with force=1 it shows soft credits by default. Without force=1, the default is to NOT show soft credits. This sets the force=1 default in line with the more common use case.

Before

$params['contributions_or_soft_credits'] being undefined means "show soft credits".

After

$params['contributions_or_soft_credits'] being undefined means "don't show soft credits".

Technical Details

The issue is that this piece of code assumes contributions_or_soft_credits is always defined, and the report defaults to contributions_only. However, this param isn't defined when force=1.

Steps to replicate are on the ticket: https://lab.civicrm.org/dev/report/issues/20

[civibot]

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