Improve LocationCard monthly statement section with proof of payment link

Changes:
- Added utilBillsProofOfPaymentAttachment to LocationCard component
- Updated monthly statement fieldset to show when proof of payment exists
- Added visual indicators with icons:
  - CheckCircleIcon next to payed total amount
  - EyeIcon for "seen by tenant" status (changed from CheckCircleIcon)
  - LinkIcon for proof of payment download link
- Added download link for proof of payment with success indicator
- Code formatting improvements and removed console.log
- Updated translations to lowercase:
  - English: "Seen by tenant" -> "seen by tenant"
  - Croatian: "Viđeno od strane podstanara" -> "viđeno od strane podstanara"
- Added Croatian translation:
  - "download-proof-of-payment-label": "potvrda-o-uplati.pdf"

The monthly statement section now displays proof of payment status
with a download link when available.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

messages/en.json

@@ -57,7 +57,7 @@
       "payed-total-label": "Payed total:",
       "link-copy-message": "Link copied to clipboard",
       "monthly-statement-legend": "Monthly statement",
-      "seen-by-tenant-label": "Seen by tenant",
+      "seen-by-tenant-label": "seen by tenant",
       "payment-info-header": "You can pay the utility bills for this month using the following information:",
       "payment-amount-label": "Amount:",
       "payment-recipient-label": "Recipient:",