Backend Metadata: reuse getPageDevice method for MetadataFile and MetadataDummy

[sfeilmeier]

This fixes an issue where a bug had been fixed only in Dummy and not in File.

See:

• https://github.com/OpenEMS/openems/blob/develop/io.openems.backend.metadata.dummy/src/io/openems/backend/metadata/dummy/MetadataDummy.java#L347
• https://github.com/OpenEMS/openems/blob/develop/io.openems.backend.metadata.file/src/io/openems/backend/metadata/file/MetadataFile.java#L356C31-L356C32

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

❗ There is a different number of reports uploaded between BASE (bb43bdf) and HEAD (d69261b). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (bb43bdf)	HEAD (d69261b)
	2	1

Additional details and impacted files

@@              Coverage Diff               @@
##             develop    #2728       +/-   ##
==============================================
- Coverage      56.01%   25.60%   -30.41%     
==============================================
  Files           2059      237     -1822     
  Lines          87511     5951    -81560     
  Branches        6420      885     -5535     
==============================================
- Hits           49013     1523    -47490     
+ Misses         36815     4354    -32461     
+ Partials        1683       74     -1609