WikiEditor: Remove old unmaintained ToC module

Change-Id: I0f53a68e50fc950d7f407ee81b2bf0d81ef4948d
WikiEditor: Remove unmaintained template editor modules

Change-Id: I47119d6cfdde4b40ff5b07be0c7d327b80598142
WikiEditor: Remove unmaintained highlight plugin

Change-Id: I9740a1197209f177217b034e8b94a90b3905a560
WikiEditor: Remove unmaintained beta iframe mode

Change-Id: I2d7369116b92d674d791e420750a906a17a46bac
Merge "WikiEditor: Remove old unmaintained ToC module"
Merge "WikiEditor: Remove unmaintained template editor modules"
Merge "WikiEditor: Remove unmaintained highlight plugin"
Merge "WikiEditor: Remove unmaintained beta iframe mode"