The linter ruleset should be versionable

At some point we will introduce the ability to treat warnings as errors. At that point, if we add a new linting rule it could be a breaking change, so we should have the ability to pin the linter rule set to a specific version in `bicepconfig.json`. Something like:

```json
{
"analyzers": {
"core": {
"ruleSetVersion": "x.y.z"
...
}
}
}
```

cc @marcusfelling @StephenWeatherford

Start by reviewing how analyzers are configured in bicepconfig.json and how the current linter rule set is selected. Define the versioning and compatibility behavior, then verify that a configured ruleSetVersion can be honored without unexpectedly changing the active rules.

Written by the indexing model from the issue text.