Take amount of reservations into account for free machine count.

[Gerrit91]

Currently it's not possible to see overbooking and also it is not possible to see how many machines are really in the pool of waiting machines because the reservations are not considered in the free count.

This PR adds the following changes:

• The faulty machine count is now always counted, independent of allocation state (this is IMHO clearer because it aligns with the output of machine issues)
• There are now dedicated counts that deal with machine allocation
  • The free machine count is now really the amount of machines that can be allocated by anyone (waiting machines that are available and not reserved).
  • A new unavailable count is introduced, which shows the machines that are not allocatable at the moment because they are not waiting or locked
  • allocated count now reflects machines that are allocated by a project
  • These three counts add up to total count
• Then there are dedicated counts for machine provisioning states, they are independent of the allocation-specific counts presented above
  • A new waiting count is introduced, which shows how many machines are in the waiting provisioning state
  • A new phoned home is introduced, which shows how many machines are in the phone home provisioning state
  • The other count shows how many machines are in another provisioning state
  • These three counts also add up to total count

Breaking Change

The partition capacity calculation was improved to include machine reservation counts. For example the free machine count is now reduced in case there is a size reservation with unused reservations for this machine size. Please adapt metrics and dashboards if necessary.

[Gerrit91]

metalctl partition capacity could then look like:

❯ m partition capacity
PARTITION   SIZE            ALLOCATED   WAITING   OTHER   TOTAL   ||   FREE   FAULTY   RESERVATIONS 
fra-equ01   c1-large-x86        2          1        0       3     ||    1       0           0         
fra-equ01   c1-xlarge-x86       6          1        1       8     ||    1       1           0         
fra-equ01   c2-large-x86        4          0        0       4     ||    0       3           0         
fra-equ01   g1-medium-x86       0          1        0       1     ||    1       1           0         
fra-equ01   n1-medium-x86       7          1        0       8     ||    0       1      0 (1/1 used)   
fra-equ01   s2-xlarge-x86       3          0        0       3     ||    0       0           0         
fra-equ01      unknown          0          0        1       1     ||    0       1           0         
    Σ                          22          4        2      28     ||    3       7           0    

[Gerrit91]

We could also add an "Unvailable" count which shows how many machines are either locked or reserved through machine state.

[Gerrit91]

I now made it like this:

❯ m partition capacity       
PARTITION   SIZE            ALLOCATED   FREE   UNAVAILABLE   RESERVATIONS   |   TOTAL   |   FAULTY 
fra-equ01   c1-large-x86    2           1      0             0              |   3       |   0        
fra-equ01   c1-xlarge-x86   6           2      0             0              |   8       |   1        
fra-equ01   c2-large-x86    4           0      0             0              |   4       |   3        
fra-equ01   g1-medium-x86   0           1      0             0              |   1       |   0        
fra-equ01   n1-medium-x86   7           0      1             0 (1/1 used)   |   8       |   0        
fra-equ01   s2-xlarge-x86   3           0      0             0              |   3       |   0        
fra-equ01   unknown         0           0      1             0              |   1       |   1        
Σ                           22          4      2             0              |   28      |   5        

❯ m partition capacity -o wide     
PARTITION   SIZE            ALLOCATED   FREE   UNAVAILABLE   RESERVATIONS   |   TOTAL   |   FAULTY   PHONED HOME   WAITING   OTHER 
fra-equ01   c1-large-x86    2           1      0             0              |   3       |   0        2             1         0       
fra-equ01   c1-xlarge-x86   6           2      0             0              |   8       |   1        6             1         1       
fra-equ01   c2-large-x86    4           0      0             0              |   4       |   3        1             0         3       
fra-equ01   g1-medium-x86   0           1      0             0              |   1       |   0        0             1         0       
fra-equ01   n1-medium-x86   7           0      1             0 (1/1 used)   |   8       |   0        7             1         0       
fra-equ01   s2-xlarge-x86   3           0      0             0              |   3       |   0        3             0         0       
fra-equ01   unknown         0           0      1             0              |   1       |   1        0             0         1       
Σ                           22          4      2             0              |   28      |   5        19            4         5