CENTR-121:Email tweaks

[don-aot]

Email template updates

Request Submitted & Access Granted emails

• Greeting: Remove recipient name from the first line — change "Hello, [name]" to "Hello,".
• Access details labels: Set "Application:" and "Access Level:" to black; only these labels are styled, values are unchanged.

Access Denied email

• Greeting: Remove recipient name from the first line — change "Hello, [name]" to "Hello,".

Access request to EAO email

• Signature: Add closing signature "EPIC.centre System".