SHOW SLAVE STATUS Reports Malformed Output For Few Invalid Values

This bug was found while testing MDEV-28302

Bug found on commit: a49aadd50c269371776572a4b9f7c7329fe47ec0

Scenario 1 :
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Start server with invalid value :

--master_ssl_crlpath="$$$$$$$$$$$$$$$"

START SLAVE and check the output of SHOW SLAVE STATUS :
Master_SSL_Crlpath: 66157661576615766157661576615766157$

Scenario 2:
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On slave :
CHANGE MASTER TO MASTER_SSL_CRLPATH="$$$$$$$$";
Master_SSL_Crlpath: $$$$$$$$

Same behavior is seen for all new string variables like master_ssl_ca,master_ssl_capath and others.

Newly introduced variables should accept and assign same values as corresponding CHANGE MASTER TO parameters.