Resolve "Resize listener for IFrame in LegacyBaseTemplate does not trigger in some cases"

Closes #813 (closed)

Closes AlekSIS-App-Hjelp#51 (closed)

added part::frontend type::bug labels

assigned to @yuha

changed target branch from master to release-3.0

added 21 commits

• 039b944a...19c0ea38 - 20 commits from branch release-3.0
• b2ac613b - Use alternative mechanism for listening to IFrame height changes in LegacyBaseTemplate

Compare with previous version

marked this merge request as ready

mentioned in issue AlekSIS-App-Hjelp#51 (closed)

changed the description

assigned to @nik and unassigned @yuha

mentioned in commit c702d9d7

merged