feat[venom]: variable range analysis

[harkal]

What I did

Add flow-sensitive range analysis and assert pruning

How I did it

How to verify it

Commit message

This commit adds `VariableRangeAnalysis` to track per-block/instruction ValueRange environments
with loop widening, evaluates arithmetic/bitwise/comparison ops and phi merges to tighten bounds 
under branch conditions.

As a minimal usage example for the analysis this commit also implements assert dropping when 
proven nonzero via range info. 

Finally it provides cover for the lattice/optimizer with unit tests.

Description for the changelog

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[codecov]

Codecov Report

❌ Patch coverage is 83.75000% with 91 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.04%. Comparing base (ae020c0) to head (6667f02).

Files with missing lines	Patch %	Lines
vyper/venom/analysis/variable_range/evaluators.py	80.48%	22 Missing and 18 partials ⚠️
vyper/venom/analysis/variable_range/analysis.py	86.23%	13 Missing and 17 partials ⚠️
vyper/venom/analysis/variable_range/value_range.py	82.35%	16 Missing and 2 partials ⚠️
vyper/venom/passes/assert_elimination.py	92.59%	1 Missing and 1 partial ⚠️
vyper/venom/ir_node_to_venom.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4790      +/-   ##
==========================================
- Coverage   93.29%   93.04%   -0.25%     
==========================================
  Files         140      145       +5     
  Lines       20277    20834     +557     
  Branches     3554     3687     +133     
==========================================
+ Hits        18917    19385     +468     
- Misses        912      963      +51     
- Partials      448      486      +38     

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