Fix type merging (mostly handling null merging properly now)

[Col-E]

See the new test case for the gist of the change.

[github-actions]

Unit Test Results

92 tests  +3   91 ✔️ +3   1s ⏱️ ±0s
12 suites ±0     1 💤 ±0 
12 files   ±0     0 ❌ ±0 

Results for commit b71b371. ± Comparison against base commit 164e39b.

This pull request removes 34 and adds 18 tests. Note that renamed tests count towards both.

		iadd
		iload a
		iload b
		ireturn	
	.code: {
	.parameters: {a, b}
	type: .enum java/lang/TargetType, METHOD
	value: "java/lang/HelloWorld", 
	}
…

me.darknet.assembler.EscapeTest ‑ [12] 







me.darknet.assembler.EscapeTest ‑ [5] @ParameterizedTest
@ValueSource(
    strings = {
        "epic\u0020obfuscated\u0020name",
        "{ \"Hello World\", type: \"java/lang/HelloWorld\" }",
        "0 -10 10f 10.16F 10.161616D 10L 0xDEADBEEF 0E10",
        ".class public java/lang/HelloWorld"
    }
)

me.darknet.assembler.SampleCompilerTest$Analysis ‑ typeInferenceListForTypedAnalysis()
me.darknet.assembler.SampleCompilerTest$Analysis ‑ typeInferenceListForValuedAnalysis()
me.darknet.assembler.SampleCompilerTest$RoundTrip ‑ [16] Example-type-infer-list.jasm
me.darknet.assembler.SampleCompilerTest$RoundTrip ‑ [17] Example-multianewarray.jasm
me.darknet.assembler.SampleCompilerTest$RoundTrip ‑ [18] Example-int-addition.jasm
me.darknet.assembler.SampleCompilerTest$RoundTrip ‑ [19] Example-int-multi.jasm
me.darknet.assembler.SampleCompilerTest$RoundTrip ‑ [20] Example-int-subtraction.jasm
me.darknet.assembler.SampleCompilerTest$RoundTrip ‑ [21] Example-getstatic.jasm
…