Lexical Editor Integration

[samueljd]

lexical editor integrated,
Currenlty the following works.

• Basic editing
• Verse, chapter, crossref,footnote.
• undo, redo , non editable mode, fontsize and font-family.
• note editor to view and edit footnotes and xref.
• book switching with new nav component without verse control
• cache mechanism for faster book loading after the initial load.
• RTL (defaults to auto. The book needs to be RTL and the projectScriptureDir should be set to the desired direction)

Some things to look out for. (Known Issues)

• The usfm grammar used is in strict mode. So files with custom tags will error out.
• The notes editor lists all the notes in a cluster.
• In some cases the notes editor may not immediately update he changes made to the notes.
• inserting chapter will insert a new para.

Limitations faced.

• most reference scripture burrito files seems to have /s5 tag that the current parser doesn't allow. Hence I reverted the reference editor to the xelah editor.
• since the reference is xelah and the main editor is lexical , the scroll sync doesn't work.
• Old usfm-grammar package is still in the package.json since other projects are using it for versification.

Things to do.

• Errors from usfm-usj convertsion to be shown to the user.
• Remove the xelah related code.

[selvabenz]

@samueljd, Please have a look at this video: the USFM import issue was fixed, but when you navigate to some other chapter the navigation bar completely disappears. i am still testing the PR.
https://www.awesomescreenshot.com/video/32086126?key=afe870ff612fa063eca27e82cfd0a3a2

[selvabenz]

@samueljd thanks for the updates and working on the issues. @vipinpaul this PR can be merged; all the mentioned issues were fixed.

• Scroll doesn't hide the toolbars -done
• Unavailable books are not clickable - done
• No content is available when there is no content in the file -done

I have found some issues in the FN and XR sections, but those issues may not be a blocker to merging the PR.