Provide a configurable map for any hardcoded metric used in implementation

[moebiusband73]

Currently at several places metric names are hardcoded. This breaks if the metric is missing or the user configured it with a different name.

Solution:
Provide a lookup map that can be configured by the user and replace any hardcoded metric name with a check in the lookup map.

[spacehamster87]

In this specific case (JobFootprint) we need four configurable arrays to allow for the following cases:

• Metrics shown in Footprint for Exclusive CPU Jobs
• Metrics shown in Footprint for Shared CPU Jobs
• Metrics shown in Footprint for Exclusive GPU Jobs
• Metrics shown in Footprint for Shared GPU Jobs

That being said, four metrics (cpu_load, flopy_any, mem_bw, mem_used) still will be required by name, for the following reasons:

• cpu_load, flopy_any, mem_bw: Averages of these metrics are persisted in the SQLite DB and will be queried first from there.
• mem_used: Logic is inverted for Footprint and has to be handled specifically -> The smaller the value, the better; This is defined in the metric thresholds.