Cache docs in local database & topic labels.

[maliming]

Resolve #2805 , resolve #1994

1. Store Document and DocumentContributors as entities into the database. Documents have different language codes and versions. Rename IDocumentStore to IDocumentSource.

2. Determine whether the file is Updor New according to the file's commits.

• Question: A new document may be modified multiple times in a short time. Although it has multiple commits, it is still a new document.

• Question: How many days have a document changed that should show the Upd label. I specify 30 days by default. https://github.com/abpframework/abp/pull/2826/files#diff-7bf979fec9bcb043de25e87457696494R127

3. Added file last modified time and contributor information.

4. We can pull single or all documents in project management. Will replace documents in the database.

[gterdem]

Added file last modified time and contributor information.

I want to suggest enhancement about this topic;
What do you think about new changes have different background color on UI for the duration of upd label so it could be easier to notice?

[maliming]

What do you think about new changes have different background color on UI for the duration of upd label so it could be easier to notice?

[Ice2burn]

Will topic be marked as UPD If you edit a typo after 30 days?

[hikalkan]

We were discussing it today :) We'll try to find a proper way (like the amount of the edit). If you have a good suggestion, it is appreciated.

[Ice2burn]

I was thinking about settings this up manually in Navigation Document. New json section "labels" or parameter "label" for example. And this problem will be closed for json-based documentation. Hovewer there is a chance that developer will forget to mark upper level nodes, but it's not your problem :)

In terms of github-based documentation, I need a bit of research to see what info available. I think New and Upd labels should appear only after version change. So checking edit date is not enough.

[hikalkan]

Following with #2843