617: loading indicator for downloading study data

[iaigner]

• fixed problem with primevue loading animations
• added loading spinner to download study data button and downlaod auditlog button
• added new confirmation dialog for navigation change
• called new confirmation dialog when user wants do navigate from download study data page to another if downlaod buffer is still going on

note: download functionality will continue, even when user navigates away but some edit functions are locked until the download is completed. the progressbar indicator will show until download starts.

Bildschirmaufnahme.2025-10-06.um.15.29.56.mov

Ticket: #617
Assignee: Isabella Aigner

[github-actions]

Test Results

0 tests  ±0   0 ✅ ±0   0s ⏱️ ±0s
0 suites ±0   0 💤 ±0 
0 files   ±0   0 ❌ ±0 

Results for commit e1356b8. ± Comparison against base commit 47dd299.

[janoliver20]

LGTM