MDEV-27033: Clean lintian 'extended-description-is-empty' errors

Fix Debian lintian errors:
  E: mariadb-plugin-provider-bzip2: extended-description-is-empty
  E: mariadb-plugin-provider-lz4: extended-description-is-empty
  E: mariadb-plugin-provider-lzma: extended-description-is-empty
  E: mariadb-plugin-provider-lzo: extended-description-is-empty
  E: mariadb-plugin-provider-snappy: extended-description-is-empty
by adding Debian Policy Manual section 3.4 (The description
of a package) extended descriptions to mariadb-plugin-provide-*
packages

debian/control

@@ -944,6 +944,13 @@ Depends: mariadb-server-10.7,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: BZip2 compression support in the server and storage engines
+ The various MariaDB storage engines, such as InnoDB, RocksDB, Mroonga,
+ can use different compression libraries.
+ .
+ Plugin provides BZip2 (https://sourceware.org/bzip2/) compression
+ .
+ Note that these affect InnoDB and Mroonga only;
+ RocksDB still uses the compression algorithms from its own library
 
 Package: mariadb-plugin-provider-lz4
 Architecture: any
@@ -951,6 +958,13 @@ Depends: mariadb-server-10.7,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: LZ4 compression support in the server and storage engines
+ The various MariaDB storage engines, such as InnoDB, RocksDB, Mroonga,
+ can use different compression libraries.
+ .
+ Plugin provides LZ4 (http://lz4.github.io/lz4/) compression
+ .
+ Note that these affect InnoDB and Mroonga only;
+ RocksDB still uses the compression algorithms from its own library
 
 Package: mariadb-plugin-provider-lzma
 Architecture: any
@@ -958,6 +972,13 @@ Depends: mariadb-server-10.7,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: LZMA compression support in the server and storage engines
+ The various MariaDB storage engines, such as InnoDB, RocksDB, Mroonga,
+ can use different compression libraries.
+ .
+ Plugin provides LZMA (https://tukaani.org/lzma/) compression
+ .
+ Note that these affect InnoDB and Mroonga only;
+ RocksDB still uses the compression algorithms from its own library
 
 Package: mariadb-plugin-provider-lzo
 Architecture: any
@@ -965,6 +986,13 @@ Depends: mariadb-server-10.7,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: LZO compression support in the server and storage engines
+ The various MariaDB storage engines, such as InnoDB, RocksDB, Mroonga,
+ can use different compression libraries.
+ .
+ Plugin provides LZO (http://www.oberhumer.com/opensource/lzo/) compression
+ .
+ Note that these affect InnoDB and Mroonga only;
+ RocksDB still uses the compression algorithms from its own library
 
 Package: mariadb-plugin-provider-snappy
 Architecture: any
@@ -972,6 +1000,13 @@ Depends: mariadb-server-10.7,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: Snappy compression support in the server and storage engines
+ The various MariaDB storage engines, such as InnoDB, RocksDB, Mroonga,
+ can use different compression libraries.
+ .
+ Plugin provides Snappy (https://github.com/google/snappy) compression
+ .
+ Note that these affect InnoDB and Mroonga only;
+ RocksDB still uses the compression algorithms from its own library
 
 Package: mariadb-test
 Architecture: any