CONTRIB/CONFIGURE: Update configure scripts to handle spaces in basedir

[Laur1nMartins]

This change allows the basedir variable to contain spaces.

What?

Adds quotes to the basedir variable.

Why?

Without them the script fails when the path contains spaces.

[tvegas1]

to unblock ci please add diff below and fix commit title with:
./contrib/squash_commit.sh -m "CONTRIB/CONFIGURE: Update configure scripts to handle spaces in basedir" -r origin/master

diff --git a/AUTHORS b/AUTHORS
index c25b3bb6a..116dfe9a2 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -59,6 +59,7 @@ Keisuke Fukuda <[email protected]>
 Ken Raffenetti <[email protected]>
 Khaled Hamidouche <[email protected]>
 Konstantin Belousov <[email protected]>
+Laurin Martins <[email protected]>
 Leonid Genkin <[email protected]>
 Lior Paz <[email protected]>
 Luis E. Pena <[email protected]>

[yosefe]

Hi @Laur1nMartins , in order to merge the patch to upstream a signed CLA is required - https://github.com/openucx/ucx/wiki/Guidance-for-contributors. Any chance you already signed it previously?