[yul-phaser] Chromosome: Add a constructor that reads steps from an abbreviation string

tools/yulPhaser/Chromosome.cpp

@@ -36,6 +36,12 @@ ostream& operator<<(ostream& _stream, Chromosome const& _chromosome);
 
 }
 
+Chromosome::Chromosome(string const& _optimisationSteps)
+{
+	for (char abbreviation: _optimisationSteps)
+		m_optimisationSteps.push_back(OptimiserSuite::stepAbbreviationToNameMap().at(abbreviation));
+}
+
 Chromosome Chromosome::makeRandom(size_t _length)
 {
 	vector<string> steps;

tools/yulPhaser/Chromosome.h

@@ -42,6 +42,7 @@ public:
 	Chromosome() = default;
 	explicit Chromosome(std::vector<std::string> _optimisationSteps):
 		m_optimisationSteps(std::move(_optimisationSteps)) {}
+	explicit Chromosome(std::string const& _optimisationSteps);
 	static Chromosome makeRandom(size_t _length);
 
 	size_t length() const { return m_optimisationSteps.size(); }