Enhance and clarify sorting options for MEASUREMENT TO STATION report

[jhaasdyk-au]

Brief description
RE: MEASUREMENT TO STATION report from --output-msr-to-stn [either for import.exe or adjust.exe]
RE: sort order argument --sort-msr-to-stn-field

The default option for --sort-msr-to-stn-field is "0. Original station order (default)".
The User Guide indicates: "By default, the measurement to station table is sorted according to station",
which suggests to me a default alphanumeric sorting (or sorting per user supplied order).
However, it appears that the sort order observed conforms to neither of these.

Consider default alphanumeric sorting.
Consider also other sorting options.

Background / Observed behaviour

For our NSW JADJ submission (not supplied here) the default sort order does:

• NOT sort by station name alpha numeric
• NOT sort by station name in order supplied in stn file
• NOT sort by station name in order supplied in msr file

Rather, the following order is provided in the .m2s file [and/or the .adj file]
How is order is determined?
All these top-of-list stations have 1x Ymsr, but thereafter don't display and obvious (to me) pattern.

ADE1        
COCO_1900001
TOW2_1900001
ANDA        
PERT_1994117
ARD2        
HOB2_1995279
ASHF        
TIDB_1900001
BAIR        
BARR        
ALIC_1900001
BDST        
...

Meanwhile, as expected, Option '1. Measurement count' returns the list (below) sorted by (1) number of obs then (2) alphanumeric within those groups.
(all stations below at top of list have 1xmsr)

00NA_1900001  
01NA_1900001  
01NA_2017124  
02NA          
10-2882_301117
1005_95000    
101_8715      
11_gocup      
12_gocup      
13_gocup 
...

Basic requirements
Depending on original intent:

• Update documentation to be more specific: is default sorting alphanumeric? or order supplier by user? or other?
• Update default sorting behaviour (if necessary)
• Extend options list:

0. Original station order (default) [i.e. as supplied by user?]
1. Alphanumeric station order
2. Measurement count (increasing)
3. Measurement count (decreasing)

Priority
[Low]

[jhaasdyk-au]

A bit of additional testing confirms:
On a small dna input dataset, the default sort order (m2s file) does indeed follow the order of stations in the stn file.

On a more complex input set,
import -n 20251022_NSW_GDA2020 20251022_NSW_GDA2020_stn.xml 20251022_NSW_GDA2020_msr.xml apref20240713.snx apref20240713_stn.xml apref20240713_msr.xml --discontinuity-file disconts20240713.snx ...
then the default sort order (m2s file) appears to be an unexpected interleaving of the first stations, in order, from the stn.xml (green highlight in image below) and the first stations, in order, from the apref.snx file. (yellow highlight in image below).
I haven't quite nutted out why it has settled on THIS order...