add new metrics + remove terraform packages from code

[tchinmai7]

Description of your changes

1. Adds new metrics introduced in upjet 1.3.0
2. Removes some terraform flags and fields from Makefile, Dockerfile
3. Bump alpine base image to match upjet-providers

Fixes #32

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

1. Run make local-deploy
2. Apply a number of different resources
3. port-forward 8080 and curl localhost:8080/metrics (snippet for random new metrics)

crossplane_managed_resource_deletion_seconds_bucket{gvk="instance.linode.upbound.io/v1alpha1, Kind=IP",le="+Inf"} 2
crossplane_managed_resource_deletion_seconds_sum{gvk="instance.linode.upbound.io/v1alpha1, Kind=IP"} 2.259376771
crossplane_managed_resource_deletion_seconds_count{gvk="instance.linode.upbound.io/v1alpha1, Kind=IP"} 2
crossplane_managed_resource_drift_seconds_bucket{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key",le="+Inf"} 1
crossplane_managed_resource_drift_seconds_sum{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key"} 7.843638795
crossplane_managed_resource_drift_seconds_count{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key"} 1
crossplane_managed_resource_first_time_to_readiness_seconds_bucket{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key",le="3600"} 1
crossplane_managed_resource_first_time_to_readiness_seconds_bucket{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key",le="+Inf"} 1
crossplane_managed_resource_first_time_to_readiness_seconds_sum{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key"} 10.02590388
crossplane_managed_resource_first_time_to_readiness_seconds_count{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key"} 1
# HELP crossplane_managed_resource_ready The number of managed resources in Ready=True state
# TYPE crossplane_managed_resource_ready gauge
crossplane_managed_resource_ready{gvk="instance.linode.upbound.io/v1alpha1, Kind=IP"} 0
crossplane_managed_resource_ready{gvk="instance.linode.upbound.io/v1alpha1, Kind=Instance"} 0
crossplane_managed_resource_ready{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Bucket"} 1
crossplane_managed_resource_ready{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key"} 0
# HELP crossplane_managed_resource_synced The number of managed resources in Synced=True state
# TYPE crossplane_managed_resource_synced gauge
crossplane_managed_resource_synced{gvk="instance.linode.upbound.io/v1alpha1, Kind=IP"} 1
crossplane_managed_resource_synced{gvk="instance.linode.upbound.io/v1alpha1, Kind=Instance"} 2
crossplane_managed_resource_synced{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Bucket"} 1
crossplane_managed_resource_synced{gvk="objectstorage.linode.upbound.io/v1alpha1, Kind=Key"} 1