XR: parse and warn on ACL udf statements

[dhalperi]

Fix #6004 - UDFs are not supported but they are warned on. cc: @SivaKesava1

[batfish-bot]

This change is 

[progwriter]

Reviewed 3 of 3 files at r1.
Reviewable status: complete! all files reviewed, all discussions resolved

[codecov]

Codecov Report

Merging #6006 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #6006      +/-   ##
============================================
+ Coverage     72.21%   72.22%   +0.01%     
- Complexity    34321    34325       +4     
============================================
  Files          2810     2810              
  Lines        140882   140882              
  Branches      16928    16928              
============================================
+ Hits         101736   101755      +19     
+ Misses        31244    31165      -79     
- Partials       7902     7962      +60     

Impacted Files	Coverage Δ	Complexity Δ
...c/main/java/org/batfish/dataplane/rib/RibTree.java	89.58% <0.00%> (-4.17%)	27.00% <0.00%> (-1.00%)
...col/src/main/java/org/batfish/role/InferRoles.java	89.54% <0.00%> (-1.37%)	50.00% <0.00%> (-1.00%)
...src/main/java/org/batfish/coordinator/PoolMgr.java	62.92% <0.00%> (-1.13%)	15.00% <0.00%> (-1.00%)
...java/org/batfish/dataplane/ibdp/VirtualRouter.java	88.04% <0.00%> (-0.32%)	262.00% <0.00%> (-2.00%)
...grammar/cisco_xr/CiscoXrControlPlaneExtractor.java	19.08% <0.00%> (+0.45%)	320.00% <0.00%> (+7.00%)
...org/batfish/representation/cisco_xr/Interface.java	52.17% <0.00%> (+2.17%)	63.00% <0.00%> (+2.00%)
...co_xr/UnimplementedAccessListServiceSpecifier.java	50.00% <0.00%> (+50.00%)	1.00% <0.00%> (+1.00%)