Fix search filter not applied and slicer reset on Fetch (#147)

[erikdarlingdata]

Summary

Two regressions from the time slicer PR (#114), both in FetchPlansForRangeAsync:

1. Search filter dropped — BuildSearchFilter() result was never passed to FetchTopPlansAsync. The call switched to named params for startUtc/endUtc and filter: was lost in the process.

2. Slicer resets to 24h on Fetch — Fetch_Click reloads slicer data via LoadTimeSlicerDataAsync, which calls LoadData without the current selection. LoadData defaults to last 24h. Now passes _slicerStartUtc/_slicerEndUtc through to preserve the user's range.

Fixes #147

Test plan

• Build succeeds (0 errors)
• Search by Module with a stored procedure name — grid shows only that proc's plans
• Search by Query ID / Plan ID / Query Hash / Plan Hash — correct filtering
• Drag slicer to custom range, click Fetch — range is preserved
• First load (no prior selection) — defaults to last 24h as before

🤖 Generated with Claude Code

[rferraton]

@erikdarlingdata : the {filterSql} in FetchTopPlansAsync is (i think) apply too late in the query : it search inside the top x. if it is what you want, no need sql. To search inside the TOPplans dataset the app already have : a filtering that reduce the list should be fast.
But if you want a deep search (the top x plans where a proc is laucn for exemple) then the filter should be apply in phase 2. That was why i was using LEFT join query_store_query_text : to apply join just in case of a filter on query_store_query_text column was done