Envupdate crossupdate fix

[RealHarshThakur]

Fixes: #1848

Functions with the environment weren't looked across namespaces.

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This change is 

[codecov]

Codecov Report

Merging #1866 (146c30c) into master (ec22e22) will decrease coverage by 7.32%.
The diff coverage is 6.12%.

@@            Coverage Diff             @@
##           master    #1866      +/-   ##
==========================================
- Coverage   28.41%   21.08%   -7.33%     
==========================================
  Files          69       52      -17     
  Lines        5040     3723    -1317     
==========================================
- Hits         1432      785     -647     
+ Misses       3390     2867     -523     
+ Partials      218       71     -147     

Impacted Files	Coverage Δ
pkg/crd/crdvalidations.go	100.00% <ø> (ø)
pkg/fission-cli/cmd/function/update.go	0.00% <ø> (ø)
pkg/router/analytics.go	0.00% <ø> (ø)
pkg/router/functionReferenceResolver.go	0.00% <0.00%> (ø)
pkg/router/httpTriggers.go	0.00% <0.00%> (ø)
pkg/router/metrics.go	88.88% <ø> (ø)
pkg/router/mutablemux.go	80.00% <ø> (ø)
pkg/router/requesthHeader.go	0.00% <ø> (ø)
pkg/router/router.go	0.00% <0.00%> (ø)
pkg/utils/rbacutils.go	0.00% <ø> (ø)
... and 21 more

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