Fixed RngWitnet#isRequestFailed so that checks the specific request id

[asselstine]

No description provided.

[linear]

GEN-1581 RngWitnet: isRequestFailed returns the latest request, not the requested request id

[github-actions]

LCOV of commit ba33ff0 during Tests with 100% Coverage #37

Summary coverage rate:
  lines......: 93.9% (31 of 33 lines)
  functions..: 100.0% (16 of 16 functions)
  branches...: no data found

Files changed coverage rate:
                   |Lines       |Functions  |Branches    
  Filename         |Rate     Num|Rate    Num|Rate     Num
  =======================================================
  src/RngWitnet.sol|96.0%     25| 100%    12|    -      0

⛔ The code coverage is too low. Expected at least 100.

[github-actions]

LCOV of commit 6cb46a8 during Tests with 100% Coverage #39

Summary coverage rate:
  lines......: 93.9% (31 of 33 lines)
  functions..: 100.0% (16 of 16 functions)
  branches...: no data found

Files changed coverage rate:
                   |Lines       |Functions  |Branches    
  Filename         |Rate     Num|Rate    Num|Rate     Num
  =======================================================
  src/RngWitnet.sol|96.0%     25| 100%    12|    -      0

⛔ The code coverage is too low. Expected at least 100.

[github-actions]

LCOV of commit fecf3cd during Tests with 100% Coverage #41

Summary coverage rate:
  lines......: 93.9% (31 of 33 lines)
  functions..: 100.0% (16 of 16 functions)
  branches...: no data found

Files changed coverage rate:
                   |Lines       |Functions  |Branches    
  Filename         |Rate     Num|Rate    Num|Rate     Num
  =======================================================
  src/RngWitnet.sol|96.0%     25| 100%    12|    -      0

⛔ The code coverage is too low. Expected at least 100.

[github-actions]

LCOV of commit 7e6e69d during Tests with 100% Coverage #45

Summary coverage rate:
  lines......: 97.0% (32 of 33 lines)
  functions..: 100.0% (16 of 16 functions)
  branches...: no data found

Files changed coverage rate:
                   |Lines       |Functions  |Branches    
  Filename         |Rate     Num|Rate    Num|Rate     Num
  =======================================================
  src/RngWitnet.sol| 100%     25| 100%    12|    -      0

⛔ The code coverage is too low. Expected at least 100.

[github-actions]

LCOV of commit 2e705d6 during Tests with 100% Coverage #47

Summary coverage rate:
  lines......: 100.0% (33 of 33 lines)
  functions..: 100.0% (16 of 16 functions)
  branches...: no data found

Files changed coverage rate:
                   |Lines       |Functions  |Branches    
  Filename         |Rate     Num|Rate    Num|Rate     Num
  =======================================================
  src/Requestor.sol| 100%      8| 100%     4|    -      0
  src/RngWitnet.sol| 100%     25| 100%    12|    -      0