Copy code for LSPTextHover from lsp4e

This is to avoid compilation issues after class
renamed in lsp4e.

If lsp4e undoes the rename as requested in this bug:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=549859

Then this commit can/should be reverted.

eclipse-language-servers/org.springframework.tooling.boot.ls/META-INF/MANIFEST.MF

@@ -26,7 +26,10 @@ Require-Bundle: org.eclipse.jdt.launching;bundle-version="3.9.0",
  org.springsource.ide.eclipse.commons.livexp,
  org.apache.commons.lang3,
  org.eclipse.wst.sse.ui;bundle-version="1.5.0";resolution:=optional,
- org.json;bundle-version="1.0.0"
+ org.json;bundle-version="1.0.0",
+ org.eclipse.jdt.annotation,
+ org.eclipse.mylyn.wikitext.markdown,
+ org.eclipse.mylyn.wikitext
 Import-Package: com.google.common.base,
  com.google.common.collect,
  com.google.gson;version="2.7.0",