Add more efficient create methods

[3ach]

Right now, to create a part, we have to do the following:

let document = new SBOLDocument();

let uriPrefix = "http://sbols.org/CRISPR_Example/";
let version = "1.0.0";

// Add top-level Component Definitions
let cas9_generic_cd = document.componentDefinition(createUri(uriPrefix, 'cas9_generic', version));
let grna_generic_cd = document.componentDefinition(createUri(uriPrefix, "gRNA_generic", version));
let cas9_grna_complex_cd = document.componentDefinition(createUri(uriPrefix, "cas9_gRNA_complex", version));
let target_gene_cd = document.componentDefinition(createUri(uriPrefix, "target_gene", version));
let target_cd = document.componentDefinition(createUri(uriPrefix, "target", version));

// Add Display IDs to component definitions
cas9_generic_cd.displayId = "cas9_generic";
grna_generic_cd.displayId = "gRNA_generic";
cas9_grna_complex_cd.displayId = "cas9_gRNA_complex";
target_gene_cd.displayId = "target_gene";
target_cd.displayId = "target";

// Add persistent identities to component definitions
cas9_generic_cd.persistentIdentity = createUri(uriPrefix, "cas9_generic");
grna_generic_cd.persistentIdentity = createUri(uriPrefix, "gRNA_generic");
cas9_grna_complex_cd.persistentIdentity = createUri(uriPrefix, "cas9_gRNA_complex");
target_gene_cd.persistentIdentity = createUri(uriPrefix, "target_gene");
target_cd.persistentIdentity = createUri(uriPrefix, "target");

// Add versions to component definitions
cas9_generic_cd.version = version;
grna_generic_cd.version = version;
cas9_grna_complex_cd.version = version;
target_gene_cd.version = version;
target_cd.version = version;

It would be better if there was a libSBOLj-style create method that allowed for something like:

let document = new SBOLDocument();

document.defaultUriPrefix = "http://sbols.org/CRISPR_Example/";
document.defaultVersion = "1.0.0";

let cas9_generic_cd = document.componentDefinition('cas9_generic');
let grna_generic_cd = document.componentDefinition("gRNA_generic");
let cas9_grna_complex_cd = document.componentDefinition("cas9_gRNA_complex");
let target_gene_cd = document.componentDefinition("target_gene");
let target_cd = document.componentDefinition("target");