Add details about license on POM

[lucasvc]

Current POM indicates as license information,

<license>
    <name>BSD</name>
    <url>LICENSE</url>
    <distribution>manual</distribution>
</license>

But readme badge clearly states as BSD3 license, leaving the POM not coherent and ambiguous (as the BSD multiple flavours).

So when using tools to analise licenses (i.e., jk1/Gradle-License-Report) requires manual review of the corresponding license.

Maybe adding in the name a term like,

• 3-Clause
• Revised
• New

would make coherent visual documentation and POM file, moreover would help automated tools.

[keilw]

I think we can do that in the current codebase (no release planned as of now) because the detail page of the JSR also says it's "a BSD 3-Clause License". Thanks for the suggestion.

[lucasvc]

Other libraries related to the JSR 385 suffer this same issue,

• tech.units:indriya
• systems.uom
• tech.uom.lib

should I open corresponding issue in each of them?