UI/Fix node-forge EC error

[hellobontempo]

Fix for #13219

Adds a catch for when node-forge returns an error converting or parsing a certificate, and returns unparsed certificate (so metadata will not display).

Addresses error returned when trying to read EC certs. Error: Cannot read public key. OID is not RSA.

When unable to parse certificate metadata, UI reverts to original behavior and just displays serial number and certificate:

[hashishaw]

Beautiful, thanks for the quick fix!

[cipherboy]

Just to mention, we tested this via setting up two secrets engines:

$ source devvault

$ vault secrets enable pki
$ vault secrets tune -max-lease-ttl=8760h pki 
$ vault write pki/root/generate/internal common_name=my-website.com ttl=8760h key_type=ec key_bits=256

$ vault secrets enable  -path=pki2/ pki
$ vault secrets tune -max-lease-ttl=8760h pki2 
$ vault write pki2/root/generate/internal common_name=my-website.com ttl=8760h key_type=rsa

One CA was with RSA and the other was with EC. Since the root CA certificate for the mount is visible from the secrets page, we were able to confirm the original issue and that this fixed it.

[Monkeychip]

Looks great. Don't forget the bug and ui label and the milestone. (unsure if this is being backported to 1.9, guessing it is?)