WIKI-748: [Unified Search] Slowness in WikiSearchServiceConnector.search

Problem analysis
	- Do not set limit value for the query to restrict the number of search result.
	- Search in nt:base nodetype space which is too large.

Fix description
	- Always set limit for each of query statement based on feature's context.
	- Re-indexing data to allow system to index parent node also contains content of child node. With that setting, we can search wiki:attachment for the content of nt:base and reduce the search space by avoid search on *nt:base* node types by searching on particular node types instead.