feat: add support for multiple metrics providers

[mowies]

This PR

• adds support for multiple KeptnMetricsProviders by introducing a new type field in the metrics provider
• adds validation to the new type field so that it can only have valid metrics provider values (i.e. prometheus | dynatrace | dql | datadog)
• adds a new API version to the metrics.keptn.sh API group (v1alpha3)
• moves the hub version to metrics.keptn.sh/v1alpha3
• adds conversion functions to older versions where needed (and also refactors some existing conversion functions into their own files)
• change the metrics kuttl integration test by removing the obsolete badmetric check and replacing it with checks for multiple providers with the same type and different names to ensure backwards compatibility of the feature

Fixes #1144

Docs will be updated in a separate PR

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[codecov]

Codecov Report

Merging #1193 (230e813) into main (99ef223) will increase coverage by 0.57%.
The diff coverage is 98.31%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1193      +/-   ##
==========================================
+ Coverage   58.94%   59.52%   +0.57%     
==========================================
  Files         128      133       +5     
  Lines       10040    10144     +104     
==========================================
+ Hits         5918     6038     +120     
+ Misses       3902     3888      -14     
+ Partials      220      218       -2     

Impacted Files	Coverage Δ
metrics-operator/api/v1alpha1/keptnmetric_types.go	100.00% <ø> (+4.00%)	⬆️
metrics-operator/api/v1alpha2/keptnmetric_types.go	100.00% <ø> (+20.00%)	⬆️
...cs-operator/api/v1alpha3/keptnmetric_conversion.go	0.00% <0.00%> (ø)
...trics-operator/api/v1alpha3/keptnmetric_webhook.go	0.00% <ø> (ø)
...tor/controllers/common/providers/datadog/common.go	86.36% <ø> (ø)
...or/controllers/common/providers/datadog/datadog.go	76.92% <ø> (ø)
...r/controllers/common/providers/dynatrace/common.go	100.00% <ø> (ø)
...ontrollers/common/providers/dynatrace/dynatrace.go	81.66% <ø> (ø)
...ollers/common/providers/dynatrace/dynatrace_dql.go	75.86% <ø> (ø)
...trollers/common/providers/prometheus/prometheus.go	85.36% <ø> (ø)
... and 6 more

... and 7 files with indirect coverage changes

Flag	Coverage Δ
certificate-operator	64.15% <ø> (ø)
component-tests	60.79% <ø> (+0.86%)	⬆️
lifecycle-operator	78.26% <ø> (+0.01%)	⬆️
metrics-operator	79.03% <98.31%> (+1.45%)	⬆️
scheduler	21.75% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[odubajDT]

awesome job :)

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[bacherfl]

nice work!