Fix [*] and ##[*] operator range minimums to be 0

[georgerennie]

According to the LRM, [*] is an equivalent representation of [*0:$] (1800-2023 p411 16.9.1) and ##[*] is used as an equivalent representation of ##[0:$] (1800-2023 p400 16.7).

With the current master build of slang (170ad7b), [*] and [*0:$] produce the following ast json respectively:

"repetition": {
  "kind": "Consecutive",
  "min": 1,
  "max": "$"
}

"repetition": {
  "kind": "Consecutive",
  "min": 0,
  "max": "$"
}

and ##[*] and ##[0:$] produce the following respectively:

{
  "sequence": {
    "kind": "Simple",
    "expr": {
      "kind": "Invalid",
      "type": "<error>"
    }
  },
  "min": 1,
  "max": "$"
}

{
  "sequence": {
    "kind": "Simple",
    "expr": {
      "kind": "Invalid",
      "type": "<error>"
    }
  },
  "min": 0,
  "max": "$"
}

These should all have the same min value of 0, but these cases weren't being handled correctly. This patch adds the special casing needed for these two scenarios, and the output now has "min": 0 for all cases.

An alternative approach could be to set the default SequenceRange::min value to 0, but I wasn't sure if other code relies on it being 1.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.72%. Comparing base (170ad7b) to head (1e41ffa).
Report is 3 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1192      +/-   ##
==========================================
- Coverage   94.72%   94.72%   -0.01%     
==========================================
  Files         202      202              
  Lines       50927    50933       +6     
==========================================
+ Hits        48243    48247       +4     
- Misses       2684     2686       +2     

Files with missing lines	Coverage Δ
source/ast/expressions/AssertionExpr.cpp	90.09% <100.00%> (-0.16%)	⬇️

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