[WIP] Generic parameter parser for scalers

[wozniakjan]

This PR intends to further improve the work related to refactoring of scalers accomplished by #5319 and #5228. This depends on #5319 and requires a rebase after that PR merges first because this contains commits from that PR.

All unique changes proposed here are in the last commit f03313c can be summarized in following points:

• dropping reflections argument from getParameterFromConfigV2 in favour of generics
• adding a type constraint to catch bugs from calling getParameterFromConfigV2 with types not supported by convertToType during compile time
• implicit type conversion so the rest of the code doesn't need type assertions

this means following invocation changes from

activationLagThreshold, err := getParameterFromConfigV2(config, activationLagThresholdMetricName, true, false, false, true, int64(defaultKafkaActivationLagThreshold), reflect.TypeOf(int64(64)))
if activationLagThreshold.(int64) < 0 {
...
}

to slightly simpler

activationLagThreshold, err := getParameterFromConfigV2(config, activationLagThresholdMetricName, true, false, false, true, defaultKafkaActivationLagThreshold)
if activationLagThreshold < 0 {
...
}

Checklist

• I have verified that my change is according to the deprecations & breaking changes policy
• Tests have been added
• Changelog has been updated and is aligned with our changelog requirements
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

Relates to #5037