Add D&B Duns number in the business details page

[marijnkampf]

Description of change

Add D&B Duns number to Companies details page.

Also refactored the file to use constant for 'Not set' text.

Test instructions

When viewing an company's details (Company > Business details) the DUNS number should be shown above Annual turnover. If not available 'Not set' should be displayed.

Screenshots

Before

With DUNS number

Without DUNS number

After

With DUNS number

Without DUNS number set

Checklist

• Has the branch been rebased to main?
• Automated tests (Any of the following when applicable: Unit, Functional or End-to-End)
• Manual compatibility testing (Browsers: Chrome, Firefox, Edge, Safari)

[cypress]

data-hub-frontend    Run #58407

Run Properties:   Passed #58407  •  a93d449c5e: Add D&B Duns number in the business details page

Project	data-hub-frontend
Branch Review	feature/CLS2-1162-add-duns-number-to-business-details
Run status	Passed #58407
Run duration	01m 38s
Commit	a93d449c5e: Add D&B Duns number in the business details page
Committer	Marijn Kampf
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	0
Pending	0
Skipped	0
Passing	15
View all changes introduced in this branch ↗︎

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.58%. Comparing base (4bc6547) to head (a93d449).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7443   +/-   ##
=======================================
  Coverage   88.58%   88.58%           
=======================================
  Files        1159     1159           
  Lines       18025    18026    +1     
  Branches     5128     5129    +1     
=======================================
+ Hits        15968    15969    +1     
  Misses       2057     2057           

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