Support for SPDX spec version 3

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This initial commit does not add any additional formats for version three. It merely updates the libraries to the latest which supports the spec version 3 format. It pass unit tests and has been tested with the latest license list and passes.

Note that this depends on unpublished versions of the SPDX Java Library and will not pass the CI tests.

Starting off with this as a draft pull request.

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This pull request is complete with the exception of the license dependencies.

Attached, for review, are a few files:

• Typical single license file (exceptions are similar): 0BSD.json
• Licenses file that catalogs all licenses (the exceptions.json is similar): licenses.json
• Archive of the website with the file structure proposed in issue 183 comment website.zip

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Fixes #187

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There were a couple significant decisions I made during implementation that deserves review. I struggled a bit with the right approach for the single license / exception format and the creator information.

• Each individual license and exception file is enclosed in an SPDX document. See SPDX model repo issue 932 for the reasons for this decision.
• I used the following creation info and creator / tools - Note: the creator agent has the version of the license list appended to the URI since the membership of the legal team may change over time.

    "@id" : "_:creationInfo_0",
    "type" : "CreationInfo",
    "specVersion" : "3.0.1",
    "createdBy" : [ "https://spdx.org/licenses/creatoragent/3_12" ],
    "createdUsing" : [ "https://spdx.org/tools/licenselistpublisher" ],
    "created" : "2021-03-07T00:00:00Z",
    "comment" : "This object is created and maintained by the SPDX legal team (https://spdx.dev/engage/participate/legal-team/) using the LicenseListPublisher (https://github.com/spdx/licenselistpublisher)"
  },  {
    "spdxId" : "https://spdx.org/tools/licenselistpublisher",
    "type" : "Tool",
    "name" : "SPDX License List Publisher",
    "creationInfo" : "_:creationInfo_0"
  }, {
    "spdxId" : "https://spdx.org/licenses/creatoragent/3_12",
    "type" : "Organization",
    "name" : "SPDX Legal Team",
    "creationInfo" : "_:creationInfo_0"
  }, ...