Allow v1,v2 etc. style version names while still supporting full semver in queries

[bep]

This enables a potentially useful workflow partitioning docs into major short versions (v1, v2 etc.). See https://github.com/bep/hugo-testing-git-versions for a runnable version.

My final setup doesn't need this PR (but I still thinks a good idea):

[versions]
    [versions.v1]
    [versions.v2]
    [versions.v3]
    [versions.dev]

[module]
    [[module.mounts]]
        source = 'content'
        target = 'content'
        [module.mounts.sites.matrix]
            versions = 'dev'
    [[module.imports]]
        ignoreConfig = true
        path         = 'github.com/bep/hugo-testing-git-versions'
        version      = '<v2.0.0'
        [[module.imports.mounts]]
            source = 'content'
            target = 'content'
            [module.imports.mounts.sites.matrix]
                versions = 'v1'
    [[module.imports]]
        ignoreConfig = true
        path         = 'github.com/bep/hugo-testing-git-versions'
        version      = '<v3.0.0'
        [[module.imports.mounts]]
            source = 'content'
            target = 'content'
            [module.imports.mounts.sites.matrix]
                versions = 'v2'
    [[module.imports]]
        ignoreConfig = true
        path         = 'github.com/bep/hugo-testing-git-versions'
        version      = '<v4.0.0'
        [[module.imports.mounts]]
            source = 'content'
            target = 'content'
            [module.imports.mounts.sites.matrix]
                versions = 'v3'

Fixes #14414