Consider scala patch version for scalac-scoverage-plugin

[sumeetgajjar]

This PR implements the approach proposed in #94. Post this it would be possible to use the maven plugin with Scala 2.12.13+

With this PR now plugin artifact lookup logic is done like below

1 First look for artifact having a name like scalac-scoverage-plugin_2.12.14 i.e. use the full version of Scala lib used in the project
2 If that artifact is not found look for scalac-scoverage-plugin_2.12

For this to work completely you still need to specify the scalacPluginVersion property. For example, with Scala 2.12.14 we need version scalac-scoverage-plugin - 1.4.8

Fixes #94

(cherry picked from commit bc925fd)

[sumeetgajjar]

This is a cherry-pick of #95. There's been no movement on #95 from Aug 2021, so I thought I would pick this up and address the reviewer's comment.

[sumeetgajjar]

@gslowikowski @sksamuel @ckipp01 could you please take a look at this PR?

[sumeetgajjar]

The CI build error for windows 8 is due to a connection reset while fetching the maven-surefire-plugin, which is unrelated to this change.

Error:  Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.22.1:test 
..
..
Connection reset -> [Help 1]

I've pushed an empty commit to trigger CI re-run.

[gslowikowski]

Merged the original PR #95