updates to MYNN-EDMF and related modules

[joeolson42]

The purpose of this PR is to update the MYNN-EDMF code in WRF to be consistent with the updated NOAA Tech Note. This same version of the MYNN-EDMF submodule will be implemented into MPAS and CCPP.

TYPE: enhancement/new features

KEYWORDS: MYNN-EDMF, turbulence, clouds, downdrafts, closure levels

SOURCE: Joseph Olson (NOAA-GSL)

DESCRIPTION OF CHANGES:
Problem(s):

1. Excessive low-level clouds, especially over water
2. prototype version of downdrafts was not well tested,
3. excessive near-surface mixing in very stable conditions.
4. Checks in module_check_a_mundo.F needed updates associated with the incoming changes. Also there was a redundant check that needed to be removed.

Solution(s):

1. revised subgrid clouds option (bl_mynn_cloudpdf = 2) improved excessive low-level clouds.
2. More testing of the downdrafts has been performed and several changes were made to improve the scale-awareness as well as the underlying physical representation of downdrafts. Still requires more testing with significantly different vertical resolution. Not active by default but considered more reliable.
3. A handful of related revisions/tunings was made to improve low level jet structures in stable conditions. This touched the LBC for TKE , Prandtl number regulation, and mixing length revision. All have been documented in the updated Tech Note (will add doi when established)
4. module_check_a_mundo.F has been modified to work with the updated MYNN-EDMF options.

LIST OF MODIFIED FILES: list of changed files (use git diff --name-status develop to get formatted list)
M Registry/Registry.EM_COMMON
M dyn_em/module_first_rk_step_part1.F
M phys/MYNN-EDMF
M phys/module_pbl_driver.F
M share/module_check_a_mundo.F

TESTS CONDUCTED:

1. WFIP3 case studies show robust improvement. Realtime testing (mostly in MPAS) show improvements relative to HRRR. Some of this was previewed in the last WRF/MPAS workshop but some more modifications have been made since.
2. Are the Jenkins tests all passing? - We'll see

RELEASE NOTE: Include a stand-alone message suitable for the inclusion in the minor and annual releases. A publication citation is appropriate.

[weiwangncar]

The regression test results:

Test Type              | Expected  | Received |  Failed
= = = = = = = = = = = = = = = = = = = = = = = =  = = = =
Number of Tests        : 23           24
Number of Builds       : 60           57
Number of Simulations  : 158           150        0
Number of Comparisons  : 95           86        0

Failed Simulations are: 
None
Which comparisons are not bit-for-bit: 
None