feat: GC log analysis support

[leveretconey]

Hi all,

This is the implementation of #107 . Target to add gclog analysis to help user deal with garbage collection issues.

Please review. Any suggestion is appreciated.

Thanks.

[leveretconey]

Hi, all. I give some additional information about how the feature is implemented to help you review the code.

Then main entrance of the feature is in GCLogAnalyzer.parse. There are 3 main steps :

1. GCLogParser will parse the original GC log file into GCEvents, recording direct information from the file. This is done by first recognizing the format and collector of the log, then parse each line using corresponding parsing rules.

2. GCModel.calculateDerivedInfo will calculate more metrics we can get from original info, such as promotion of single event and max pause time of the whole process. All these data are saved in GCModel.

3. Frontend pages displays information through gclog backend apis.

Please review. Thanks.

[D-D-H]

${vertx_version}

[leveretconey]

fixed