RFR: 6973: New Method Profiling Page for JMC [v2]

[Jean-Philippe Bempel]

> Tabs for Predecessors and Successors instead of Packages/Classes
> 
> ![JMC_MethodProfiling_Pred](https://user-images.githubusercontent.com/4610701/100017066-a1774200-2dda-11eb-80c1-9113478a307b.png)
> 
> ![JMC_MethodProfiling_Suc](https://user-images.githubusercontent.com/4610701/100017088-aa681380-2dda-11eb-8374-f2e30c8d2b22.png)

Jean-Philippe Bempel has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:

 - Fix Successor tree
   
   Add method formatter context menu
 - 6973: New Method Profiling Page for JMC
   
   Tabs for Predecessors and Successors instead of Packages/Classes

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Changes: https://git.openjdk.java.net/jmc/pull/165/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jmc&pr=165&range=01
  Stats: 661 lines in 5 files changed: 574 ins; 21 del; 66 mod
  Patch: https://git.openjdk.java.net/jmc/pull/165.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/165/head:pull/165

PR: https://git.openjdk.java.net/jmc/pull/165