internal/report/human: add fingerprint, split resource rows

[jroimartin]

This PR implements two changes in Lava's human-readable output:

• Show vulnerability fingerprint, so it is easier to exclude
  vulnerabilities by this criteria.
• Split resource rows with hyphens, so it is easier to read the
  resource tables.

Before,

=== [GO-2021-0113] Out-of-bounds read in golang.org/x/text/language (HIGH) ===

TARGET
/home/n/tmp/govulncheck-test/

AFFECTED RESOURCE
Module golang.org/x/[email protected] at sub1/go.mod:1

DESCRIPTION
Out-of-bounds read in golang.org/x/text/language

DETAILS
Your code calls vulnerable functions in 1 package (golang.org/x/text/language).

RECOMMENDATIONS
- Visit the linked references for more details.

REFERENCES
- https://pkg.go.dev/vuln/GO-2021-0113

RESOURCES
- A summarized code flow for vulnerable function golang.org/x/text/language.Parse:
  module: sub1@
  location: %SRCROOT%/main.go:12:29
  function: sub1.main
  module: golang.org/x/[email protected]
  location: %GOMODCACHE%/golang.org/x/[email protected]/language/parse.go:33:6
  function: golang.org/x/text/language.Parse

After,

=== [GO-2021-0113] Out-of-bounds read in golang.org/x/text/language (HIGH) ===

TARGET
/home/n/tmp/govulncheck-test/

AFFECTED RESOURCE
Module golang.org/x/[email protected] at sub1/go.mod:1

FINGERPRINT
30832915d775c6f522564e815d0322facca4598bf72427ad5c93281026b351a6

DESCRIPTION
Out-of-bounds read in golang.org/x/text/language

DETAILS
Your code calls vulnerable functions in 1 package (golang.org/x/text/language).

RECOMMENDATIONS
- Visit the linked references for more details.

REFERENCES
- https://pkg.go.dev/vuln/GO-2021-0113

RESOURCES
- A summarized code flow for vulnerable function golang.org/x/text/language.Parse:
  - module: sub1@
    location: %SRCROOT%/main.go:12:29
    function: sub1.main
  - module: golang.org/x/[email protected]
    location: %GOMODCACHE%/golang.org/x/[email protected]/language/parse.go:33:6
    function: golang.org/x/text/language.Parse