Mam/report wrong stanza id more friendly

[NelsonVides]

If a client submits a stanza id that is not a valid one as generated by MIM's MAM, MAM is failing with a hard crash and returning the client a 500. This is not really friendly and doesn't help in debugging what went wrong.

In this PR I make it catch such an invalid id and return a more friendly 406-non_acceptable error, with a text description.

[codecov]

Codecov Report

Merging #3591 (2f6b47e) into master (02b6471) will decrease coverage by 0.04%.
The diff coverage is 87.50%.

@@            Coverage Diff             @@
##           master    #3591      +/-   ##
==========================================
- Coverage   80.92%   80.88%   -0.05%     
==========================================
  Files         426      426              
  Lines       32351    32364      +13     
==========================================
- Hits        26181    26178       -3     
- Misses       6170     6186      +16     

Impacted Files	Coverage Δ
src/mam/mod_mam.erl	88.44% <85.71%> (-0.13%)	⬇️
src/mam/mod_mam_muc.erl	74.76% <85.71%> (+0.74%)	⬆️
src/mam/mod_mam_utils.erl	85.94% <100.00%> (+0.04%)	⬆️
src/event_pusher/mod_event_pusher_sns.erl	83.11% <0.00%> (-11.69%)	⬇️
src/rdbms/mongoose_rdbms.erl	62.54% <0.00%> (-1.82%)	⬇️
src/inbox/mod_inbox_rdbms_async.erl	65.51% <0.00%> (-1.73%)	⬇️
src/mod_blocking.erl	88.46% <0.00%> (-1.29%)	⬇️
src/domain/mongoose_domain_loader.erl	89.28% <0.00%> (-0.90%)	⬇️
src/privacy/mod_privacy.erl	85.00% <0.00%> (-0.84%)	⬇️
src/privacy/mod_privacy_rdbms.erl	77.94% <0.00%> (-0.52%)	⬇️
... and 7 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 02b6471...2f6b47e. Read the comment docs.

[mongoose-im]

small_tests_24 / small_tests / 2f6b47e
Reports root / small

---

small_tests_23 / small_tests / 2f6b47e
Reports root / small

---

dynamic_domains_pgsql_mnesia_23 / pgsql_mnesia / 2f6b47e
Reports root/ big
OK: 2821 / Failed: 0 / User-skipped: 133 / Auto-skipped: 0

---

dynamic_domains_mysql_redis_24 / mysql_redis / 2f6b47e
Reports root/ big
OK: 2804 / Failed: 0 / User-skipped: 150 / Auto-skipped: 0

---

dynamic_domains_pgsql_mnesia_24 / pgsql_mnesia / 2f6b47e
Reports root/ big
OK: 2821 / Failed: 0 / User-skipped: 133 / Auto-skipped: 0

---

ldap_mnesia_23 / ldap_mnesia / 2f6b47e
Reports root/ big
OK: 1504 / Failed: 0 / User-skipped: 399 / Auto-skipped: 0

---

dynamic_domains_mssql_mnesia_24 / odbc_mssql_mnesia / 2f6b47e
Reports root/ big
OK: 2821 / Failed: 0 / User-skipped: 133 / Auto-skipped: 0

---

ldap_mnesia_24 / ldap_mnesia / 2f6b47e
Reports root/ big
OK: 1504 / Failed: 0 / User-skipped: 399 / Auto-skipped: 0

---

internal_mnesia_24 / internal_mnesia / 2f6b47e
Reports root/ big
OK: 1545 / Failed: 0 / User-skipped: 358 / Auto-skipped: 0

---

elasticsearch_and_cassandra_24 / elasticsearch_and_cassandra_mnesia / 2f6b47e
Reports root/ big
OK: 1852 / Failed: 0 / User-skipped: 366 / Auto-skipped: 0

---

pgsql_mnesia_24 / pgsql_mnesia / 2f6b47e
Reports root/ big
OK: 3195 / Failed: 0 / User-skipped: 142 / Auto-skipped: 0

---

pgsql_mnesia_23 / pgsql_mnesia / 2f6b47e
Reports root/ big
OK: 3195 / Failed: 0 / User-skipped: 142 / Auto-skipped: 0

---

mysql_redis_24 / mysql_redis / 2f6b47e
Reports root/ big
OK: 3190 / Failed: 0 / User-skipped: 147 / Auto-skipped: 0

---

mssql_mnesia_24 / odbc_mssql_mnesia / 2f6b47e
Reports root/ big
OK: 3195 / Failed: 0 / User-skipped: 142 / Auto-skipped: 0

---

riak_mnesia_24 / riak_mnesia / 2f6b47e
Reports root/ big
OK: 1695 / Failed: 0 / User-skipped: 365 / Auto-skipped: 0

[arcusfelis]

ok