debuginfod: PR27982 - added DEBUGINFOD_MAXSIZE and DEBUGINFOD_MAXTIME

debuginfod: PR27982 - added DEBUGINFOD_MAXSIZE and DEBUGINFOD_MAXTIME

DEBUGINFOD_TIMEOUT is a good way to catch servers that are too slow to
*start* transmitting a file.  But we have no way of limiting total
download time or space.  A user might prefer to have his debugger fetch
only quick & small files, and make do without the bigger ones.  Some
transitive dependencies of e.g. gnome programs are huge: 3GB of LLVM
debuginfo, 1GB of webkitgtk, etc. etc.
DEBUGINFOD_MAXSIZE and DEBUGINFOD_MAXTIME were added to dictate the
max download size and time of a debuginfod client. DEBUGINFOD_MAXSIZE
is handled server-side and is sent using the http header:
X-DEBUGINFOD-MAXSIZE. The client side then checks to ensure this maxsize
has been respected.

https://sourceware.org/bugzilla/show_bug.cgi?id=27982

Signed-off-by: Noah Sanci <nsanci@redhat.com>