validate sample and patient before render the patient view

[dippindots]

validate sample and patient before render the patient view
Fix # cBioPortal/cbioportal#5357.

Changes proposed in this pull request:

• a show error when sample or patient not exists
  

[dippindots]

test links:

1. sample
2. patient

[alisman]

@dippindots
For this case, we should not say "URL invalid." The URL form is valid, it's just that the ID doesn't exist. So, error message should be that Patient doesn't exist.

[alisman]

I think this check belongs in the patientViewStore, not here.

[alisman]

When a user submits a request with invalid sample/patient, we already get 404s. So we can accomplish this ticket by properly handling those errors states for the existing mobx promises. In other words, we should just show a message when we detect isError=true

here is example
https://www.cbioportal.org/patient?studyId=ucec_tcga_pub&caseId=TCG-BK-A0CC

[dippindots]

@alisman solution updated, test links:

1. sample
2. patient