Use "major version" and "minor version" for syntactic versions

[sdboyer]

Thema's versioning system has two digits, e.g. v0.0 - what people coming from semver would be naturally inclined to call a "major version" and a "minor version."

i resisted this naming initially, for reasons i can't even remember. Instead, i've been calling the first number "sequence version" and the second "schema version." But this was an error. For one, "schema version" is confusingly ambiguous - is that the second number, or the version number as a whole? And second, the cost of asking people to learn new terms for version number positions is significantly higher than the risk of having folks transfer possibly-slightly-incorrect associations from semver.

Putting me over the top on this was the fact that OpenMetadata landed on major.minor with exactly the same semantics.

So - all docs need to be updated to use major and minor where appropriate. Variables and fields should be renamed from e.g. seqv and schv to majv and minv.

[frossano-grafana]

@rhorvath can we look at this PR and see if it's good to be merged, and close the issue?