renter: update renter methods to used cached values for siafile when necessary

4 jobs for 3423-use-cached-siafile-values in 34 minutes and 14 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Lint
passed #169653230
lint

00:03:53

 
  Test
failed #169653233
integration-tests

00:30:20

75.0%
passed #169653231
legacy-tests

00:28:12

51.5%
passed #169653232
package-tests

00:20:35

87.3%
 
Name Stage Failure
failed
integration-tests Test
coverage: 75.0% of statements
ok gitlab.com/NebulousLabs/Sia/siatest/wallet 51.618s coverage: 75.0% of statements
Makefile:99: recipe for target 'test-long' failed
make: *** [test-long] Error 1
Uploading artifacts...
WARNING: /builds/NebulousLabs/Sia/SiaTesting: no matching files
WARNING: /builds/NebulousLabs/Sia/cover/cover.out: no matching files
ERROR: No files to upload
ERROR: Job failed: exit code 1