[FE-9355] smarter timestamp casting

[int3h]

:speech_balloon: Description

Per discussion from @wamsiv, timestamp casts (specifically for combo chart range bounds) are now redundant; the Core should automatically cast as appropriate. According to Todd, these CASTs are significantly hurting query performance. So I'm removing that CAST from SQL generation.

Note: I also changed the upper range calculation for time ranges. Previously, we took the ms-precision timestamp (so, seconds + three decimal points of ms precision) and appended the string 999999 (for nanosecond precision), and used <= upperBound. Now, I take the ms-precision timestamp, add 1ms, and use < upperBound.

Merge Checklist

:wrench: Issue(s) fixed:

• [x] Author referenced issue(s) fixed by this PR:
• [x] Fixes FE-9355

:smoking: Smoke Test

• [x] Works in chrome
• [ ] Works in firefox
• [ ] Works in safari
• [ ] Works in ie edge
• [ ] Works in ie 11

:ship: Merge

• [x] author crafted PR's title into release-worthy commit message.

[tmostak]

Can we please time this vs master (and any other proposed options) to ensure it's a performance win? Might try in both cpu and gpu mode at some scale, as well as timestamps of various precisions (0,3,6,9)?