fix: Remove multiple SemVer incompatibilities in tagFormat

[AndriyGo]

Current implementation is non SemVer compliant in many cases. For example:

• Doesn't allow passing build metadata Cannot pass build number to use in tag format #3308
• Compiles v${version}a to a valid tag even though it is NOT a valid SemVer tag

This PR addresses this issue by making sure that when analysing tags, and when publishing them, SemVer compliance is mostly followed.

Mostly because there is 1 notable exception – any prefix is allowed preceding the ${version}. So, even though pre-1.1.1 is not strictly SemVer compliant – it is allowed.

I would summarise this PR with the following table:

+-------------+------------------+-------------------+--------------+
|     tag     |    tagFormat     | version (Current) | version (PR) |
+-------------+------------------+-------------------+--------------+
| v1.1.0      | v${version}      | 1.1.0             | 1.1.0        |
| v1.1.0+abcd | v${version}      | -                 | 1.1.0        |
| v1.1.0+(3)  | v${version}      | -                 | -            |
| v1.1.0a+bcd | v${version}      | -                 | -            |
| v1.1.0a     | v${version}      | -                 | -            |
| ----------- | ---------------- | ----------------- | ------------ |
| v1.1.0      | v${version}+abcd | -                 | 1.1.0        |
| v1.1.0+abcd | v${version}+abcd | 1.1.0             | 1.1.0        |
| v1.1.0+(3)  | v${version}+abcd | -                 | -            |
| v1.1.0a+bcd | v${version}+abcd | -                 | -            |
| v1.1.0a     | v${version}+abcd | -                 | -            |
| ----------- | ---------------- | ----------------- | ------------ |
| v1.1.0      | v${version}+(3)  | -                 | error        |
| v1.1.0+abcd | v${version}+(3)  | -                 | error        |
| v1.1.0+(3)  | v${version}+(3)  | 1.1.0             | error        |
| v1.1.0a+bcd | v${version}+(3)  | -                 | error        |
| v1.1.0a     | v${version}+(3)  | -                 | error        |
| ----------- | ---------------- | ----------------- | ------------ |
| v1.1.0      | v${version}a     | -                 | error        |
| v1.1.0+abcd | v${version}a     | -                 | error        |
| v1.1.0+(3)  | v${version}a     | -                 | error        |
| v1.1.0a+bcd | v${version}a     | -                 | error        |
| v1.1.0a     | v${version}a     | 1.1.0             | error        |
+-------------+------------------+-------------------+--------------+

@travi please have a look. Apart from containing build meta – this PR does improve tag processing in various other ways making it more compatible with SemVer

[travi]

closing as mentioned in #3308 (comment)