Add config option for import timeout

[luhring]

Closes #419

Adds a new CLI flag (--import-timeout) and backing config option ("anchore.import-timeout") to Syft. This allows the user to control the timeout duration applied to the image SBOM import operation. By default, this value is set to 30 seconds.

[github-actions]

Benchmark Test Results

Benchmark results from the latest changes vs base branch

name                                                   old time/op    new time/op    delta
ImagePackageCatalogers/ruby-gemspec-cataloger-2           899µs ± 2%     891µs ± 3%    ~     (p=0.690 n=5+5)
ImagePackageCatalogers/python-package-cataloger-2        1.19ms ± 3%    1.22ms ± 3%    ~     (p=0.095 n=5+5)
ImagePackageCatalogers/javascript-package-cataloger-2     457µs ± 1%     471µs ± 5%    ~     (p=0.548 n=5+5)
ImagePackageCatalogers/dpkgdb-cataloger-2                 437µs ± 2%     418µs ± 3%  -4.30%  (p=0.016 n=5+5)
ImagePackageCatalogers/rpmdb-cataloger-2                  464µs ± 3%     441µs ± 1%  -5.14%  (p=0.008 n=5+5)
ImagePackageCatalogers/java-cataloger-2                  6.12ms ± 2%    6.01ms ± 1%    ~     (p=0.095 n=5+5)
ImagePackageCatalogers/apkdb-cataloger-2                  647µs ± 1%     650µs ± 1%    ~     (p=0.421 n=5+5)
ImagePackageCatalogers/go-cataloger-2                     225µs ± 0%     224µs ± 2%    ~     (p=0.730 n=4+5)
ImagePackageCatalogers/rust-cataloger-2                   361µs ± 1%     355µs ± 4%    ~     (p=0.548 n=5+5)

name                                                   old alloc/op   new alloc/op   delta
ImagePackageCatalogers/ruby-gemspec-cataloger-2          97.6kB ± 0%    97.5kB ± 0%    ~     (p=0.222 n=5+5)
ImagePackageCatalogers/python-package-cataloger-2         579kB ± 0%     579kB ± 0%    ~     (p=0.841 n=5+5)
ImagePackageCatalogers/javascript-package-cataloger-2     112kB ± 0%     112kB ± 0%    ~     (p=0.389 n=5+5)
ImagePackageCatalogers/dpkgdb-cataloger-2                 115kB ± 0%     115kB ± 0%    ~     (p=0.095 n=5+5)
ImagePackageCatalogers/rpmdb-cataloger-2                  134kB ± 0%     134kB ± 0%    ~     (p=0.135 n=5+5)
ImagePackageCatalogers/java-cataloger-2                  1.78MB ± 0%    1.78MB ± 0%    ~     (p=1.000 n=5+5)
ImagePackageCatalogers/apkdb-cataloger-2                 1.14MB ± 0%    1.14MB ± 0%    ~     (p=0.095 n=5+5)
ImagePackageCatalogers/go-cataloger-2                    48.3kB ± 0%    48.3kB ± 0%  -0.09%  (p=0.008 n=5+5)
ImagePackageCatalogers/rust-cataloger-2                  88.9kB ± 0%    88.9kB ± 0%  +0.02%  (p=0.008 n=5+5)

name                                                   old allocs/op  new allocs/op  delta
ImagePackageCatalogers/ruby-gemspec-cataloger-2           1.96k ± 0%     1.96k ± 0%    ~     (all equal)
ImagePackageCatalogers/python-package-cataloger-2         5.89k ± 0%     5.89k ± 0%    ~     (all equal)
ImagePackageCatalogers/javascript-package-cataloger-2     1.93k ± 0%     1.93k ± 0%    ~     (all equal)
ImagePackageCatalogers/dpkgdb-cataloger-2                 2.37k ± 0%     2.37k ± 0%    ~     (all equal)
ImagePackageCatalogers/rpmdb-cataloger-2                  3.19k ± 0%     3.19k ± 0%    ~     (all equal)
ImagePackageCatalogers/java-cataloger-2                   22.3k ± 0%     22.3k ± 0%    ~     (p=0.683 n=5+5)
ImagePackageCatalogers/apkdb-cataloger-2                  1.85k ± 0%     1.85k ± 0%    ~     (all equal)
ImagePackageCatalogers/go-cataloger-2                     1.40k ± 0%     1.40k ± 0%    ~     (all equal)
ImagePackageCatalogers/rust-cataloger-2                   2.75k ± 0%     2.75k ± 0%    ~     (all equal)