Allow fwhm_fromlines for tilts calibration

[debora-pe]

As title. Addresses issue #1688
Also, a small fix to pypeit_chk_tilts

[codecov]

Codecov Report

Attention: Patch coverage is 31.57895% with 13 lines in your changes missing coverage. Please review.

Project coverage is 38.07%. Comparing base (2b53647) to head (7a3944e).

Files with missing lines	Patch %	Lines
pypeit/wavetilts.py	33.33%	10 Missing ⚠️
pypeit/scripts/chk_tilts.py	0.00%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #1861   +/-   ##
========================================
  Coverage    38.07%   38.07%           
========================================
  Files          211      211           
  Lines        49051    49064   +13     
========================================
+ Hits         18675    18680    +5     
- Misses       30376    30384    +8     

Flag	Coverage Δ
	?

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.