[GR-5233] Package test analyzer improvements.

...acle/truffle/r/test/packages/analyzer/FileTreeWalker.java

.../com/oracle/truffle/r/test/packages/analyzer/Problem.java

...ackages/analyzer/detectors/SymbolLookupErrorDetector.java

...truffle/r/test/packages/analyzer/dump/AbstractDumper.java

...cle/truffle/r/test/packages/analyzer/dump/HTMLDumper.java

...uffle/r/test/packages/analyzer/model/RPackageTestRun.java

...ruffle/r/test/packages/analyzer/parser/LogFileParser.java