Make schema valid

[sverhoeven]

Uploading a workflow with a pdb file that can not be parsed by https://github.com/douweschulte/pdbtbx would cause a invalid JSON schema to be generated, which in turn made the upload fail to be loaded.

Workflow builder gives:

chunk-NW63JG7V.js:28 Error: schema is invalid: data/properties/mol/items must be object,boolean, data/properties/mol/items/0/properties/hisd/items/enum must NOT have fewer than 1 items, data/properties/mol/items/0/properties/hisd/items must be array, data/properties/mol/items/0/properties/hisd/items must match a schema in anyOf, data/properties/mol/items must match a schema in anyOf
    at Ajv3.validateSchema (core.ts:519:18)
    at Ajv3._addSchema (core.ts:721:30)
    at Ajv3.compile (core.ts:384:22)
    at Ajv3.validate (core.ts:361:16)
    at validateParameters (chunk-GRSI6OON.js:67:12)
    at chunk-GRSI6OON.js:45:26
    at Array.map (<anonymous>)
    at validateWorkflow (chunk-GRSI6OON.js:32:38)
    at async loadWorkflowArchive (chunk-CFUCBIDV.js:25:18)
    at async loadWorkflowArchive (chunk-UMXYOHQW.js:343:17)

This PR fixes this error.

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[codecov-commenter]

Codecov Report

Merging #129 (1a90151) into main (e7fbcac) will increase coverage by 0.01%. The diff coverage is 75.00%.

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@@            Coverage Diff             @@
##             main     #129      +/-   ##
==========================================
+ Coverage   66.62%   66.64%   +0.01%     
==========================================
  Files          57       57              
  Lines        4033     4035       +2     
  Branches      332      334       +2     
==========================================
+ Hits         2687     2689       +2     
+ Misses       1343     1342       -1     
- Partials        3        4       +1     

Flag	Coverage Δ
core-unit	63.64% <75.00%> (+0.02%)	:arrow_up:
form-unit	78.50% <ø> (ø)

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Files	Coverage Δ
...ackages/core/src/molecule/addMoleculeValidation.ts	92.85% <75.00%> (+0.04%)	:arrow_up: