fix(version): Handle pkgbase with '.' correctly

For pkgbases with '.' in the name, the TOML-section must be wrapped in
double quotes in order for it not to be parsed as a supersection and a
subsection. This case was not properly handled by checks for if the
TOML-file contains a pkgbase section, and for if the TOML-file contains
superfluous sections. Address this by handling optional double quotes in
the greps related to said checks.

This was discovered in the AUR package ruby-cool.io and the issue can be
reproduced with the following minimal PKGBUILD and .nvchecker.toml file:

    $ cat PKGBUILD
    pkgname=ruby-cool.io
    pkgver=1.8.0
    $ cat .nvchecker.toml
    ["ruby-cool.io"]
    source = "gems"
    gems = "cool.io"

Before the fix:

    $ pkgctl version check
    Failure
     x ruby-cool.io: missing pkgbase section in .nvchecker.toml: ruby-cool.io

After the fix:

    $ pkgctl version check
    GEN lib/version/check.sh
    Out-of-date
     ✓ ruby-cool.io: current version 1.8.0 is latest

Component: pkgctl version check

0 files changed, 0 insertions, 0 deletions