[MDS-6701] BE error on submitting document categories

[taraepp]

Objective

This was the BE error that was coming up behind the "internal server error":

• I had at one point accidentally used "SPT" to refer to Supporting documents (SPT is already in use for Spatial)
• when I fixed it, I missed the bit on the FE 🤦‍♀️
• so it was sending an invalid value back to the BE when "Supporting documents --> Supporting documents" was selected

MDS-6701

[sonarqubecloud]

Quality Gate passed for 'bcgov-sonarcloud_mds_minespace-web'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'bcgov-sonarcloud_mds_common'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'bcgov-sonarcloud_mds_core-web'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud