Add miglayout-swing and pin to version 5.2

[imagejan]

This is used in SearchBarHacker, but wasn't declared explicitly so far.

Until miglayout-swing is used across the SciJava software stack, we need to exclude miglayout from other dependencies.

• The exclusions can be removed once https://github.com/scijava/scijava-ui-awt/pull/1, https://github.com/scijava/scijava-ui-swing/pull/46, https://github.com/scijava/script-editor/pull/40, and https://github.com/scijava/scijava-search/pull/17 are all merged and released.
• The version pinning can be removed once we have a pom-scijava release managing this version (see https://github.com/scijava/pom-scijava/pull/97).