TIMOB-6949 add the header only if that contains the filter value

[bijupmb]

https://jira.appcelerator.org/browse/TIMOB-6949

[hieupham007]

This code adds additional headers into the tableview, instead of hiding empty headers. Basically every time we call "index.add(i)", we're adding a row into the tableview, whether it is a header or an actually row.
Here we should have checks to see if the header is empty. If it is, don't add it. You can check for empty header by looking at next values: i.e if item(i) is a header and item(i+1) is a footer or header, we know that it's item(i) is an empty header.
Note that this is just one condition for empty headers(the real solution probably would need more checks since there are a few edge cases we have to consider). The goal here is to HIDE all empty headers AND footers.

[bijupmb]

changed
New PR :
#4764

[hieupham007]

Code reviewed. Please address comments.

[bijupmb]

created new PR

[hieupham007]

closing this PR