TLM Grapher no data

[EmilyRagan]

Describe the bug

TLM Grapher sets X axis to start at 1/1/1970 and shows no data

To Reproduce

1. Go to Telemetry Grapher
2. Add an item that has data
3. Edit the graph
4. Set the start and end date/time to a region of time that does not have data for the item
5. Save

Second workflow:

1. Go to Telemetry Grapher
2. Add 2 items that have data
3. Edit the graph
4. Set the start and end date/time to a region of time that does not have data for just one of the items (the other has data during this period)
5. Save

Expected behavior

X axis should be start-to-end time with no data
Maybe have a warning of "no data"
Data should be shown for any item(s) that do have data during the selected time

Screenshots

OS

No response

OpenC3 COSMOS Version

7.0.0

Browser

No response